Chang S. Bae [Fri, 25 Nov 2022 12:58:41 +0000 (20:58 +0800)]
x86: KVM: Advertise AMX-FP16 CPUID to user space
Latest Intel platform Granite Rapids has introduced a new instruction -
AMX-FP16, which performs dot-products of two FP16 tiles and accumulates
the results into a packed single precision tile. AMX-FP16 adds FP16
capability and also allows a FP16 GPU trained model to run faster
without loss of accuracy or added SW overhead.
The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 21]
AMX-FP16 is on an expected-dense CPUID leaf and some other bits on this
leaf have kernel usages. Given that, define this feature bit like
X86_FEATURE_<name> in kernel. Considering AMX-FP16 itself has no truly
kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
one in /proc/cpuinfo.
Advertise AMX-FP16 to KVM userspace. This is safe because there are no
new VMX controls or additional host enabling required for guests to use
this feature.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Message-Id: <
20221125125845.1182922-5-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Jiaxi Chen [Fri, 25 Nov 2022 12:58:40 +0000 (20:58 +0800)]
x86: KVM: Advertise CMPccXADD CPUID to user space
CMPccXADD is a new set of instructions in the latest Intel platform
Sierra Forest. This new instruction set includes a semaphore operation
that can compare and add the operands if condition is met, which can
improve database performance.
The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 7]
CMPccXADD is on an expected-dense CPUID leaf and some other bits on this
leaf have kernel usages. Given that, define this feature bit like
X86_FEATURE_<name> in kernel. Considering CMPccXADD itself has no truly
kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
one in /proc/cpuinfo.
Advertise CMPCCXADD to KVM userspace. This is safe because there are no
new VMX controls or additional host enabling required for guests to use
this feature.
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Message-Id: <
20221125125845.1182922-4-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 25 Nov 2022 12:58:39 +0000 (20:58 +0800)]
KVM: x86: Update KVM-only leaf handling to allow for 100% KVM-only leafs
Rename kvm_cpu_cap_init_scattered() to kvm_cpu_cap_init_kvm_defined() in
anticipation of adding KVM-only CPUID leafs that aren't recognized by the
kernel and thus not scattered, i.e. for leafs that are 100% KVM-defined.
Adjust/add comments to kvm_only_cpuid_leafs and KVM_X86_FEATURE to
document how to create new kvm_only_cpuid_leafs entries for scattered
features as well as features that are entirely unknown to the kernel.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20221125125845.1182922-3-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Fri, 25 Nov 2022 12:58:38 +0000 (20:58 +0800)]
KVM: x86: Add BUILD_BUG_ON() to detect bad usage of "scattered" flags
Add a compile-time assert in the SF() macro to detect improper usage,
i.e. to detect passing in an X86_FEATURE_* flag that isn't actually
scattered by the kernel. Upcoming feature flags will be 100% KVM-only
and will have X86_FEATURE_* macros that point at a kvm_only_cpuid_leafs
word, not a kernel-defined word. Using SF() and thus boot_cpu_has() for
such feature flags would access memory beyond x86_capability[NCAPINTS]
and at best incorrectly hide a feature, and at worst leak kernel state to
userspace.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20221125125845.1182922-2-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Woodhouse [Sat, 12 Nov 2022 14:28:20 +0000 (14:28 +0000)]
MAINTAINERS: Add KVM x86/xen maintainer list
Adding Paul as co-maintainer of Xen support to help ensure that things
don't fall through the cracks when I spend three months at a time
travelling...
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Woodhouse [Mon, 14 Nov 2022 20:48:57 +0000 (12:48 -0800)]
KVM: x86/xen: Add CPL to Xen hypercall tracepoint
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 24 Nov 2022 00:40:01 +0000 (19:40 -0500)]
KVM: always declare prototype for kvm_arch_irqchip_in_kernel
Architecture code might want to use it even if CONFIG_HAVE_KVM_IRQ_ROUTING
is false; for example PPC XICS has KVM_IRQ_LINE and wants to use
kvm_arch_irqchip_in_kernel from there, but it does not have
KVM_SET_GSI_ROUTING so the prototype was not provided.
Fixes:
d663b8a28598 ("KVM: replace direct irq.h inclusion")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 23 Nov 2022 23:52:29 +0000 (18:52 -0500)]
Merge branch 'kvm-dwmw2-fixes' into HEAD
This brings in a few important fixes for Xen emulation.
While nobody should be enabling it, the bug effectively
allows userspace to read arbitrary memory.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Woodhouse [Sat, 19 Nov 2022 09:25:39 +0000 (09:25 +0000)]
KVM: Update gfn_to_pfn_cache khva when it moves within the same page
In the case where a GPC is refreshed to a different location within the
same page, we didn't bother to update it. Mostly we don't need to, but
since the ->khva field also includes the offset within the page, that
does have to be updated.
Fixes:
3ba2c95ea180 ("KVM: Do not incorporate page offset into gfn=>pfn cache user address")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Woodhouse [Sat, 12 Nov 2022 13:52:25 +0000 (13:52 +0000)]
KVM: x86/xen: Only do in-kernel acceleration of hypercalls for guest CPL0
There are almost no hypercalls which are valid from CPL > 0, and definitely
none which are handled by the kernel.
Fixes:
2fd6df2f2b47 ("KVM: x86/xen: intercept EVTCHNOP_send from guests")
Reported-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Woodhouse [Sat, 12 Nov 2022 13:48:58 +0000 (13:48 +0000)]
KVM: x86/xen: Validate port number in SCHEDOP_poll
We shouldn't allow guests to poll on arbitrary port numbers off the end
of the event channel table.
Fixes:
1a65105a5aba ("KVM: x86/xen: handle PV spinlocks slowpath")
[dwmw2: my bug though; the original version did check the validity as a
side-effect of an idr_find() which I ripped out in refactoring.]
Reported-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:26 +0000 (15:54 +0100)]
KVM: selftests: Rename 'evmcs_test' to 'hyperv_evmcs'
Conform to the rest of Hyper-V emulation selftests which have 'hyperv'
prefix. Get rid of '_test' suffix as well as the purpose of this code
is fairly obvious.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-49-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:25 +0000 (15:54 +0100)]
KVM: selftests: hyperv_svm_test: Introduce L2 TLB flush test
Enable Hyper-V L2 TLB flush and check that Hyper-V TLB flush hypercalls
from L2 don't exit to L1 unless 'TlbLockCount' is set in the Partition
assist page.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-48-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:24 +0000 (15:54 +0100)]
KVM: selftests: evmcs_test: Introduce L2 TLB flush test
Enable Hyper-V L2 TLB flush and check that Hyper-V TLB flush hypercalls
from L2 don't exit to L1 unless 'TlbLockCount' is set in the
Partition assist page.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-47-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:23 +0000 (15:54 +0100)]
KVM: selftests: Introduce rdmsr_from_l2() and use it for MSR-Bitmap tests
Hyper-V MSR-Bitmap tests do RDMSR from L2 to exit to L1. While 'evmcs_test'
correctly clobbers all GPRs (which are not preserved), 'hyperv_svm_test'
does not. Introduce a more generic rdmsr_from_l2() to avoid code
duplication and remove hardcoding of MSRs. Do not put it in common code
because it is really just a selftests bug rather than a processor
feature that requires it.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-46-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:22 +0000 (15:54 +0100)]
KVM: selftests: Stuff RAX/RCX with 'safe' values in vmmcall()/vmcall()
vmmcall()/vmcall() are used to exit from L2 to L1 and no concrete hypercall
ABI is currenty followed. With the introduction of Hyper-V L2 TLB flush
it becomes (theoretically) possible that L0 will take responsibility for
handling the call and no L1 exit will happen. Prevent this by stuffing RAX
(KVM ABI) and RCX (Hyper-V ABI) with 'safe' values.
While on it, convert vmmcall() to 'static inline', make it setup stack
frame and move to include/x86_64/svm_util.h.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-45-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:21 +0000 (15:54 +0100)]
KVM: selftests: Allocate Hyper-V partition assist page
In preparation to testing Hyper-V L2 TLB flush hypercalls, allocate
so-called Partition assist page.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-44-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:20 +0000 (15:54 +0100)]
KVM: selftests: Create a vendor independent helper to allocate Hyper-V specific test pages
There's no need to pollute VMX and SVM code with Hyper-V specific
stuff and allocate Hyper-V specific test pages for all test as only
few really need them. Create a dedicated struct and an allocation
helper.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-43-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:19 +0000 (15:54 +0100)]
KVM: selftests: Split off load_evmcs() from load_vmcs()
In preparation to putting Hyper-V specific test pages to a dedicated
struct, move eVMCS load logic from load_vmcs(). Tests call load_vmcs()
directly and the only one which needs 'enlightened' version is
evmcs_test so there's not much gain in having this merged.
Temporary pass both GPA and HVA to load_evmcs().
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-42-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:18 +0000 (15:54 +0100)]
KVM: selftests: Move Hyper-V VP assist page enablement out of evmcs.h
Hyper-V VP assist page is not eVMCS specific, it is also used for
enlightened nSVM. Move the code to vendor neutral place.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-41-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:17 +0000 (15:54 +0100)]
KVM: selftests: Sync 'struct hv_vp_assist_page' definition with hyperv-tlfs.h
'struct hv_vp_assist_page' definition doesn't match TLFS. Also, define
'struct hv_nested_enlightenments_control' and use it instead of opaque
'__u64'.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-40-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:16 +0000 (15:54 +0100)]
KVM: selftests: Sync 'struct hv_enlightened_vmcs' definition with hyperv-tlfs.h
'struct hv_enlightened_vmcs' definition in selftests is not '__packed'
and so we rely on the compiler doing the right padding. This is not
obvious so it seems beneficial to use the same definition as in kernel.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-39-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:15 +0000 (15:54 +0100)]
KVM: selftests: Hyper-V PV TLB flush selftest
Introduce a selftest for Hyper-V PV TLB flush hypercalls
(HvFlushVirtualAddressSpace/HvFlushVirtualAddressSpaceEx,
HvFlushVirtualAddressList/HvFlushVirtualAddressListEx).
The test creates one 'sender' vCPU and two 'worker' vCPU which do busy
loop reading from a certain GVA checking the observed value. Sender
vCPU swaos the data page with another page filled with a different value.
The expectation for workers is also altered. Without TLB flush on worker
vCPUs, they may continue to observe old value. To guard against accidental
TLB flushes for worker vCPUs the test is repeated 100 times.
Hyper-V TLB flush hypercalls are tested in both 'normal' and 'XMM
fast' modes.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-38-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:13 +0000 (15:54 +0100)]
KVM: selftests: Export vm_vaddr_unused_gap() to make it possible to request unmapped ranges
Currently, tests can only request a new vaddr range by using
vm_vaddr_alloc()/vm_vaddr_alloc_page()/vm_vaddr_alloc_pages() but
these functions allocate and map physical pages too. Make it possible
to request unmapped range too.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-36-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:12 +0000 (15:54 +0100)]
KVM: selftests: Fill in vm->vpages_mapped bitmap in virt_map() too
Similar to vm_vaddr_alloc(), virt_map() needs to reflect the mapping
in vm->vpages_mapped.
While on it, remove unneeded code wrapping in vm_vaddr_alloc().
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-35-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:11 +0000 (15:54 +0100)]
KVM: selftests: Hyper-V PV IPI selftest
Introduce a selftest for Hyper-V PV IPI hypercalls
(HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx).
The test creates one 'sender' vCPU and two 'receiver' vCPU and then
issues various combinations of send IPI hypercalls in both 'normal'
and 'fast' (with XMM input where necessary) mode. Later, the test
checks whether IPIs were delivered to the expected destination vCPU[s].
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-34-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:10 +0000 (15:54 +0100)]
KVM: selftests: Move the function doing Hyper-V hypercall to a common header
All Hyper-V specific tests issuing hypercalls need this.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-33-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:09 +0000 (15:54 +0100)]
KVM: selftests: Move HYPERV_LINUX_OS_ID definition to a common header
HYPERV_LINUX_OS_ID needs to be written to HV_X64_MSR_GUEST_OS_ID by
each Hyper-V specific selftest.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-32-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:08 +0000 (15:54 +0100)]
KVM: selftests: Better XMM read/write helpers
set_xmm()/get_xmm() helpers are fairly useless as they only read 64 bits
from 128-bit registers. Moreover, these helpers are not used. Borrow
_kvm_read_sse_reg()/_kvm_write_sse_reg() from KVM limiting them to
XMM0-XMM8 for now.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-31-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:07 +0000 (15:54 +0100)]
KVM: x86: Expose Hyper-V L2 TLB flush feature
With both nSVM and nVMX implementations in place, KVM can now expose
Hyper-V L2 TLB flush feature to userspace.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-30-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:06 +0000 (15:54 +0100)]
KVM: nSVM: hyper-v: Enable L2 TLB flush
Implement Hyper-V L2 TLB flush for nSVM. The feature needs to be enabled
both in extended 'nested controls' in VMCB and VP assist page.
According to Hyper-V TLFS, synthetic vmexit to L1 is performed with
- HV_SVM_EXITCODE_ENL exit_code.
- HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH exit_info_1.
Note: VP assist page is cached in 'struct kvm_vcpu_hv' so
recalc_intercepts() doesn't need to read from guest's memory. KVM
needs to update the case upon each VMRUN and after svm_set_nested_state
(svm_get_nested_state_pages()) to handle the case when the guest got
migrated while L2 was running.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-29-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:05 +0000 (15:54 +0100)]
KVM: x86: Make kvm_hv_get_assist_page() return 0/-errno
Convert kvm_hv_get_assist_page() to return 'int' and propagate possible
errors from kvm_read_guest_cached().
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-28-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:04 +0000 (15:54 +0100)]
KVM: nVMX: hyper-v: Enable L2 TLB flush
Enable L2 TLB flush feature on nVMX when:
- Enlightened VMCS is in use.
- The feature flag is enabled in eVMCS.
- The feature flag is enabled in partition assist page.
Perform synthetic vmexit to L1 after processing TLB flush call upon
request (HV_VMX_SYNTHETIC_EXIT_REASON_TRAP_AFTER_FLUSH).
Note: nested_evmcs_l2_tlb_flush_enabled() uses cached VP assist page copy
which gets updated from nested_vmx_handle_enlightened_vmptrld(). This is
also guaranteed to happen post migration with eVMCS backed L2 running.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-27-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:03 +0000 (15:54 +0100)]
KVM: nVMX: hyper-v: Cache VP assist page in 'struct kvm_vcpu_hv'
In preparation to enabling L2 TLB flush, cache VP assist page in
'struct kvm_vcpu_hv'. While on it, rename nested_enlightened_vmentry()
to nested_get_evmptr() and make it return eVMCS GPA directly.
No functional change intended.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-26-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:02 +0000 (15:54 +0100)]
KVM: x86: hyper-v: Introduce fast guest_hv_cpuid_has_l2_tlb_flush() check
Introduce a helper to quickly check if KVM needs to handle VMCALL/VMMCALL
from L2 in L0 to process L2 TLB flush requests.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-25-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:01 +0000 (15:54 +0100)]
KVM: x86: hyper-v: L2 TLB flush
Handle L2 TLB flush requests by going through all vCPUs and checking
whether there are vCPUs running the same VM_ID with a VP_ID specified
in the requests. Perform synthetic exit to L2 upon finish.
Note, while checking VM_ID/VP_ID of running vCPUs seem to be a bit
racy, we count on the fact that KVM flushes the whole L2 VPID upon
transition. Also, KVM_REQ_HV_TLB_FLUSH request needs to be done upon
transition between L1 and L2 to make sure all pending requests are
always processed.
For the reference, Hyper-V TLFS refers to the feature as "Direct
Virtual Flush".
Note, nVMX/nSVM code does not handle VMCALL/VMMCALL from L2 yet.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-24-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:54:00 +0000 (15:54 +0100)]
KVM: x86: hyper-v: Introduce kvm_hv_is_tlb_flush_hcall()
The newly introduced helper checks whether vCPU is performing a
Hyper-V TLB flush hypercall. This is required to filter out L2 TLB
flush hypercalls for processing.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-23-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:59 +0000 (15:53 +0100)]
KVM: x86: Introduce .hv_inject_synthetic_vmexit_post_tlb_flush() nested hook
Hyper-V supports injecting synthetic L2->L1 exit after performing
L2 TLB flush operation but the procedure is vendor specific. Introduce
.hv_inject_synthetic_vmexit_post_tlb_flush nested hook for it.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-22-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:58 +0000 (15:53 +0100)]
KVM: nSVM: Keep track of Hyper-V hv_vm_id/hv_vp_id
Similar to nSVM, KVM needs to know L2's VM_ID/VP_ID and Partition
assist page address to handle L2 TLB flush requests.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-21-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:57 +0000 (15:53 +0100)]
KVM: nVMX: Keep track of hv_vm_id/hv_vp_id when eVMCS is in use
To handle L2 TLB flush requests, KVM needs to keep track of L2's VM_ID/
VP_IDs which are set by L1 hypervisor. 'Partition assist page' address is
also needed to handle post-flush exit to L1 upon request.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-20-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:56 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Use preallocated buffer in 'struct kvm_vcpu_hv' instead of on-stack 'sparse_banks'
To make kvm_hv_flush_tlb() ready to handle L2 TLB flush requests, KVM needs
to allow for all 64 sparse vCPU banks regardless of KVM_MAX_VCPUs as L1
may use vCPU overcommit for L2. To avoid growing on-stack allocation, make
'sparse_banks' part of per-vCPU 'struct kvm_vcpu_hv' which is allocated
dynamically.
Note: sparse_set_to_vcpu_mask() can't currently be used to handle L2
requests as KVM does not keep L2 VM_ID -> L2 VCPU_ID -> L1 vCPU mappings,
i.e. its vp_bitmap array is still bounded by the number of L1 vCPUs and so
can remain an on-stack allocation.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-19-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:55 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Create a separate fifo for L2 TLB flush
To handle L2 TLB flush requests, KVM needs to use a separate fifo from
regular (L1) Hyper-V TLB flush requests: e.g. when a request to flush
something in L2 is made, the target vCPU can transition from L2 to L1,
receive a request to flush a GVA for L1 and then try to enter L2 back.
The first request needs to be processed at this point. Similarly,
requests to flush GVAs in L1 must wait until L2 exits to L1.
No functional change as KVM doesn't handle L2 TLB flush requests from
L2 yet.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-18-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:54 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Don't use sparse_set_to_vcpu_mask() in kvm_hv_send_ipi()
Get rid of on-stack allocation of vcpu_mask and optimize kvm_hv_send_ipi()
for a smaller number of vCPUs in the request. When Hyper-V TLB flush
is in use, HvSendSyntheticClusterIpi{,Ex} calls are not commonly used to
send IPIs to a large number of vCPUs (and are rarely used in general).
Introduce hv_is_vp_in_sparse_set() to directly check if the specified
VP_ID is present in sparse vCPU set.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-17-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:53 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Use HV_MAX_SPARSE_VCPU_BANKS/HV_VCPUS_PER_SPARSE_BANK instead of raw '64'
It may not be clear from where the '64' limit for the maximum sparse
bank number comes from, use HV_MAX_SPARSE_VCPU_BANKS define instead.
Use HV_VCPUS_PER_SPARSE_BANK in KVM_HV_MAX_SPARSE_VCPU_SET_BITS's
definition. Opportunistically adjust the comment around BUILD_BUG_ON().
No functional change.
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-16-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:52 +0000 (15:53 +0100)]
x86/hyperv: Introduce HV_MAX_SPARSE_VCPU_BANKS/HV_VCPUS_PER_SPARSE_BANK constants
It may not come clear from where the magical '64' value used in
__cpumask_to_vpset() come from. Moreover, '64' means both the maximum
sparse bank number as well as the number of vCPUs per bank. Add defines
to make things clear. These defines are also going to be used by KVM.
No functional change.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-15-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:51 +0000 (15:53 +0100)]
KVM: x86: Prepare kvm_hv_flush_tlb() to handle L2's GPAs
To handle L2 TLB flush requests, KVM needs to translate the specified
L2 GPA to L1 GPA to read hypercall arguments from there.
No functional change as KVM doesn't handle VMCALL/VMMCALL from L2 yet.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-14-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:50 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Expose support for extended gva ranges for flush hypercalls
Extended GVA ranges support bit seems to indicate whether lower 12
bits of GVA can be used to specify up to 4095 additional consequent
GVAs to flush. This is somewhat described in TLFS.
Previously, KVM was handling HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX}
requests by flushing the whole VPID so technically, extended GVA
ranges were already supported. As such requests are handled more
gently now, advertizing support for extended ranges starts making
sense to reduce the size of TLB flush requests.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-13-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:49 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently
Currently, HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls are handled
the exact same way as HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE{,EX}: by
flushing the whole VPID and this is sub-optimal. Switch to handling
these requests with 'flush_tlb_gva()' hooks instead. Use the newly
introduced TLB flush fifo to queue the requests.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-12-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 1 Nov 2022 14:53:48 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Add helper to read hypercall data for array
Move the guts of kvm_get_sparse_vp_set() to a helper so that the code for
reading a guest-provided array can be reused in the future, e.g. for
getting a list of virtual addresses whose TLB entries need to be flushed.
Opportunisticaly swap the order of the data and XMM adjustment so that
the XMM/gpa offsets are bundled together.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-11-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:47 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Introduce TLB flush fifo
To allow flushing individual GVAs instead of always flushing the whole
VPID a per-vCPU structure to pass the requests is needed. Use standard
'kfifo' to queue two types of entries: individual GVA (GFN + up to 4095
following GFNs in the lower 12 bits) and 'flush all'.
The size of the fifo is arbitrarily set to '16'.
Note, kvm_hv_flush_tlb() only queues 'flush all' entries for now and
kvm_hv_vcpu_flush_tlb() doesn't actually read the fifo just resets the
queue before returning -EOPNOTSUPP (which triggers full TLB flush) so
the functional change is very small but the infrastructure is prepared
to handle individual GVA flush requests.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-10-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:46 +0000 (15:53 +0100)]
KVM: x86: hyper-v: Resurrect dedicated KVM_REQ_HV_TLB_FLUSH flag
In preparation to implementing fine-grained Hyper-V TLB flush and
L2 TLB flush, resurrect dedicated KVM_REQ_HV_TLB_FLUSH request bit. As
KVM_REQ_TLB_FLUSH_GUEST is a stronger operation, clear KVM_REQ_HV_TLB_FLUSH
request in kvm_vcpu_flush_tlb_guest().
The flush itself is temporary handled by kvm_vcpu_flush_tlb_guest().
No functional change intended.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-9-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 1 Nov 2022 14:53:45 +0000 (15:53 +0100)]
KVM: x86: Move clearing of TLB_FLUSH_CURRENT to kvm_vcpu_flush_tlb_all()
Clear KVM_REQ_TLB_FLUSH_CURRENT in kvm_vcpu_flush_tlb_all() instead of in
its sole caller that processes KVM_REQ_TLB_FLUSH. Regardless of why/when
kvm_vcpu_flush_tlb_all() is called, flushing "all" TLB entries also
flushes "current" TLB entries.
Ideally, there will never be another caller of kvm_vcpu_flush_tlb_all(),
and moving the handling "requires" extra work to document the ordering
requirement, but future Hyper-V paravirt TLB flushing support will add
similar logic for flush "guest" (Hyper-V can flush a subset of "guest"
entries). And in the Hyper-V case, KVM needs to do more than just clear
the request, the queue of GPAs to flush also needs to purged, and doing
all only in the request path is undesirable as kvm_vcpu_flush_tlb_guest()
does have multiple callers (though it's unlikely KVM's paravirt TLB flush
will coincide with Hyper-V's paravirt TLB flush).
Move the logic even though it adds extra "work" so that KVM will be
consistent with how flush requests are processed when the Hyper-V support
lands.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-8-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:44 +0000 (15:53 +0100)]
KVM: VMX: Rename "vmx/evmcs.{ch}" to "vmx/hyperv.{ch}"
To conform with SVM, rename VMX specific Hyper-V files from "evmcs.{ch}"
to "hyperv.{ch}". While Enlightened VMCS is a lion's share of these
files, some stuff (e.g. enlightened MSR bitmap, the upcoming Hyper-V
L2 TLB flush, ...) goes beyond that.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-7-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Tue, 1 Nov 2022 14:53:43 +0000 (15:53 +0100)]
KVM: x86: Rename 'enable_direct_tlbflush' to 'enable_l2_tlb_flush'
To make terminology between Hyper-V-on-KVM and KVM-on-Hyper-V consistent,
rename 'enable_direct_tlbflush' to 'enable_l2_tlb_flush'. The change
eliminates the use of confusing 'direct' and adds the missing underscore.
No functional change.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 1 Nov 2022 14:53:42 +0000 (15:53 +0100)]
x86/hyperv: KVM: Rename "hv_enlightenments" to "hv_vmcb_enlightenments"
Now that KVM isn't littered with "struct hv_enlightenments" casts, rename
the struct to "hv_vmcb_enlightenments" to highlight the fact that the
struct is specifically for SVM's VMCB.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 1 Nov 2022 14:53:41 +0000 (15:53 +0100)]
KVM: SVM: Add a proper field for Hyper-V VMCB enlightenments
Add a union to provide hv_enlightenments side-by-side with the sw_reserved
bytes that Hyper-V's enlightenments overlay. Casting sw_reserved
everywhere is messy, confusing, and unnecessarily unsafe.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 1 Nov 2022 14:53:40 +0000 (15:53 +0100)]
KVM: selftests: Move "struct hv_enlightenments" to x86_64/svm.h
Move Hyper-V's VMCB "struct hv_enlightenments" to the svm.h header so
that the struct can be referenced in "struct vmcb_control_area".
Alternatively, a dedicated header for SVM+Hyper-V could be added, a la
x86_64/evmcs.h, but it doesn't appear that Hyper-V will end up needing
a wholesale replacement for the VMCB.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sean Christopherson [Tue, 1 Nov 2022 14:53:39 +0000 (15:53 +0100)]
x86/hyperv: Move VMCB enlightenment definitions to hyperv-tlfs.h
Move Hyper-V's VMCB enlightenment definitions to the TLFS header; the
definitions come directly from the TLFS[*], not from KVM.
No functional change intended.
[*] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/datatypes/hv_svm_enlightened_vmcb_fields
[vitaly: rename VMCB_HV_ -> HV_VMCB_ to match the rest of
hyperv-tlfs.h, keep svm/hyperv.h]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <
20221101145426.251680-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 17 Nov 2022 17:25:02 +0000 (12:25 -0500)]
KVM: x86: avoid memslot check in NX hugepage recovery if it cannot succeed
Since gfn_to_memslot() is relatively expensive, it helps to
skip it if it the memslot cannot possibly have dirty logging
enabled. In order to do this, add to struct kvm a counter
of the number of log-page memslots. While the correct value
can only be read with slots_lock taken, the NX recovery thread
is content with using an approximate value. Therefore, the
counter is an atomic_t.
Based on https://lore.kernel.org/kvm/
20221027200316.2221027-2-dmatlack@google.com/
by David Matlack.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 17 Nov 2022 16:50:23 +0000 (11:50 -0500)]
Merge branch 'kvm-svm-harden' into HEAD
This fixes three issues in nested SVM:
1) in the shutdown_interception() vmexit handler we call kvm_vcpu_reset().
However, if running nested and L1 doesn't intercept shutdown, the function
resets vcpu->arch.hflags without properly leaving the nested state.
This leaves the vCPU in inconsistent state and later triggers a kernel
panic in SVM code. The same bug can likely be triggered by sending INIT
via local apic to a vCPU which runs a nested guest.
On VMX we are lucky that the issue can't happen because VMX always
intercepts triple faults, thus triple fault in L2 will always be
redirected to L1. Plus, handle_triple_fault() doesn't reset the vCPU.
INIT IPI can't happen on VMX either because INIT events are masked while
in VMX mode.
Secondarily, KVM doesn't honour SHUTDOWN intercept bit of L1 on SVM.
A normal hypervisor should always intercept SHUTDOWN, a unit test on
the other hand might want to not do so.
Finally, the guest can trigger a kernel non rate limited printk on SVM
from the guest, which is fixed as well.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:51 +0000 (16:13 +0200)]
KVM: x86: remove exit_int_info warning in svm_handle_exit
It is valid to receive external interrupt and have broken IDT entry,
which will lead to #GP with exit_int_into that will contain the index of
the IDT entry (e.g any value).
Other exceptions can happen as well, like #NP or #SS
(if stack switch fails).
Thus this warning can be user triggred and has very little value.
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-10-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:50 +0000 (16:13 +0200)]
KVM: selftests: add svm part to triple_fault_test
Add a SVM implementation to triple_fault_test to test that
emulated/injected shutdown works.
Since instead of the VMX, the SVM allows the hypervisor to avoid
intercepting shutdown in guest, don't intercept shutdown to test that
KVM suports this correctly.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-9-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:49 +0000 (16:13 +0200)]
KVM: x86: allow L1 to not intercept triple fault
This is SVM correctness fix - although a sane L1 would intercept
SHUTDOWN event, it doesn't have to, so we have to honour this.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-8-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:48 +0000 (16:13 +0200)]
kvm: selftests: add svm nested shutdown test
Add test that tests that on SVM if L1 doesn't intercept SHUTDOWN,
then L2 crashes L1 and doesn't crash L2
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-7-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:47 +0000 (16:13 +0200)]
KVM: selftests: move idt_entry to header
struct idt_entry will be used for a test which will break IDT on purpose.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:46 +0000 (16:13 +0200)]
KVM: x86: forcibly leave nested mode on vCPU reset
While not obivous, kvm_vcpu_reset() leaves the nested mode by clearing
'vcpu->arch.hflags' but it does so without all the required housekeeping.
On SVM, it is possible to have a vCPU reset while in guest mode because
unlike VMX, on SVM, INIT's are not latched in SVM non root mode and in
addition to that L1 doesn't have to intercept triple fault, which should
also trigger L1's reset if happens in L2 while L1 didn't intercept it.
If one of the above conditions happen, KVM will continue to use vmcb02
while not having in the guest mode.
Later the IA32_EFER will be cleared which will lead to freeing of the
nested guest state which will (correctly) free the vmcb02, but since
KVM still uses it (incorrectly) this will lead to a use after free
and kernel crash.
This issue is assigned CVE-2022-3344
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-5-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:45 +0000 (16:13 +0200)]
KVM: x86: add kvm_leave_nested
add kvm_leave_nested which wraps a call to nested_ops->leave_nested
into a function.
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:44 +0000 (16:13 +0200)]
KVM: x86: nSVM: harden svm_free_nested against freeing vmcb02 while still in use
Make sure that KVM uses vmcb01 before freeing nested state, and warn if
that is not the case.
This is a minimal fix for CVE-2022-3344 making the kernel print a warning
instead of a kernel panic.
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Thu, 3 Nov 2022 14:13:43 +0000 (16:13 +0200)]
KVM: x86: nSVM: leave nested mode on vCPU free
If the VM was terminated while nested, we free the nested state
while the vCPU still is in nested mode.
Soon a warning will be added for this condition.
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <
20221103141351.50662-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Matlack [Thu, 3 Nov 2022 20:44:21 +0000 (13:44 -0700)]
KVM: x86/mmu: Do not recover dirty-tracked NX Huge Pages
Do not recover (i.e. zap) an NX Huge Page that is being dirty tracked,
as it will just be faulted back in at the same 4KiB granularity when
accessed by a vCPU. This may need to be changed if KVM ever supports
2MiB (or larger) dirty tracking granularity, or faulting huge pages
during dirty tracking for reads/executes. However for now, these zaps
are entirely wasteful.
In order to check if this commit increases the CPU usage of the NX
recovery worker thread I used a modified version of execute_perf_test
[1] that supports splitting guest memory into multiple slots and reports
/proc/pid/schedstat:se.sum_exec_runtime for the NX recovery worker just
before tearing down the VM. The goal was to force a large number of NX
Huge Page recoveries and see if the recovery worker used any more CPU.
Test Setup:
echo 1000 > /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms
echo 10 > /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio
Test Command:
./execute_perf_test -v64 -s anonymous_hugetlb_1gb -x 16 -o
| kvm-nx-lpage-re:se.sum_exec_runtime |
| ---------------------------------------- |
Run | Before | After |
------- | ------------------ | ------------------- |
1 | 730.084105 | 724.375314 |
2 | 728.751339 | 740.581988 |
3 | 736.264720 | 757.078163 |
Comparing the median results, this commit results in about a 1% increase
CPU usage of the NX recovery worker when testing a VM with 16 slots.
However, the effect is negligible with the default halving time of NX
pages, which is 1 hour rather than 10 seconds given by period_ms = 1000,
ratio = 10.
[1] https://lore.kernel.org/kvm/
20221019234050.3919566-2-dmatlack@google.com/
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <
20221103204421.1146958-1-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 17 Nov 2022 16:05:51 +0000 (11:05 -0500)]
KVM: x86/mmu: simplify kvm_tdp_mmu_map flow when guest has to retry
A removed SPTE is never present, hence the "if" in kvm_tdp_mmu_map
only fails in the exact same conditions that the earlier loop
tested in order to issue a "break". So, instead of checking twice the
condition (upper level SPTEs could not be created or was frozen), just
exit the loop with a goto---the usual poor-man C replacement for RAII
early returns.
While at it, do not use the "ret" variable for return values of
functions that do not return a RET_PF_* enum. This is clearer
and also makes it possible to initialize ret to RET_PF_RETRY.
Suggested-by: Robert Hoo <robert.hu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Matlack [Wed, 9 Nov 2022 18:59:05 +0000 (10:59 -0800)]
KVM: x86/mmu: Split huge pages mapped by the TDP MMU on fault
Now that the TDP MMU has a mechanism to split huge pages, use it in the
fault path when a huge page needs to be replaced with a mapping at a
lower level.
This change reduces the negative performance impact of NX HugePages.
Prior to this change if a vCPU executed from a huge page and NX
HugePages was enabled, the vCPU would take a fault, zap the huge page,
and mapping the faulting address at 4KiB with execute permissions
enabled. The rest of the memory would be left *unmapped* and have to be
faulted back in by the guest upon access (read, write, or execute). If
guest is backed by 1GiB, a single execute instruction can zap an entire
GiB of its physical address space.
For example, it can take a VM longer to execute from its memory than to
populate that memory in the first place:
$ ./execute_perf_test -s anonymous_hugetlb_1gb -v96
Populating memory : 2.748378795s
Executing from memory : 2.899670885s
With this change, such faults split the huge page instead of zapping it,
which avoids the non-present faults on the rest of the huge page:
$ ./execute_perf_test -s anonymous_hugetlb_1gb -v96
Populating memory : 2.729544474s
Executing from memory : 0.111965688s <---
This change also reduces the performance impact of dirty logging when
eager_page_split=N. eager_page_split=N (abbreviated "eps=N" below) can
be desirable for read-heavy workloads, as it avoids allocating memory to
split huge pages that are never written and avoids increasing the TLB
miss cost on reads of those pages.
| Config: ept=Y, tdp_mmu=Y, 5% writes |
| Iteration 1 dirty memory time |
| --------------------------------------------- |
vCPU Count | eps=N (Before) | eps=N (After) | eps=Y |
------------ | -------------- | ------------- | ------------ |
2 | 0.332305091s | 0.019615027s | 0.006108211s |
4 | 0.353096020s | 0.019452131s | 0.006214670s |
8 | 0.453938562s | 0.019748246s | 0.006610997s |
16 | 0.719095024s | 0.019972171s | 0.007757889s |
32 | 1.698727124s | 0.021361615s | 0.012274432s |
64 | 2.630673582s | 0.031122014s | 0.016994683s |
96 | 3.016535213s | 0.062608739s | 0.044760838s |
Eager page splitting remains beneficial for write-heavy workloads, but
the gap is now reduced.
| Config: ept=Y, tdp_mmu=Y, 100% writes |
| Iteration 1 dirty memory time |
| --------------------------------------------- |
vCPU Count | eps=N (Before) | eps=N (After) | eps=Y |
------------ | -------------- | ------------- | ------------ |
2 | 0.317710329s | 0.296204596s | 0.058689782s |
4 | 0.337102375s | 0.299841017s | 0.060343076s |
8 | 0.386025681s | 0.297274460s | 0.060399702s |
16 | 0.791462524s | 0.298942578s | 0.062508699s |
32 | 1.719646014s | 0.313101996s | 0.075984855s |
64 | 2.527973150s | 0.455779206s | 0.079789363s |
96 | 2.681123208s | 0.673778787s | 0.165386739s |
Further study is needed to determine if the remaining gap is acceptable
for customer workloads or if eager_page_split=N still requires a-priori
knowledge of the VM workload, especially when considering these costs
extrapolated out to large VMs with e.g. 416 vCPUs and 12TB RAM.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Message-Id: <
20221109185905.486172-3-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 17 Nov 2022 14:03:55 +0000 (09:03 -0500)]
Merge tag 'kvm-selftests-6.2-1' of https://github.com/kvm-x86/linux into HEAD
KVM selftests updates for 6.2
perf_util:
- Add support for pinning vCPUs in dirty_log_perf_test.
- Add a lightweight psuedo RNG for guest use, and use it to randomize
the access pattern and write vs. read percentage in the so called
"perf util" tests.
- Rename the so called "perf_util" framework to "memstress".
ucall:
- Add a common pool-based ucall implementation (code dedup and pre-work
for running SEV (and beyond) guests in selftests.
- Fix an issue in ARM's single-step test when using the new pool-based
implementation; LDREX/STREX don't play nice with single-step exceptions.
init:
- Provide a common constructor and arch hook, which will eventually be
used by x86 to automatically select the right hypercall (AMD vs. Intel).
x86:
- Clean up x86's page tabe management.
- Clean up and enhance the "smaller maxphyaddr" test, and add a related
test to cover generic emulation failure.
- Clean up the nEPT support checks.
- Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.
David Matlack [Wed, 16 Nov 2022 20:42:28 +0000 (12:42 -0800)]
KVM: selftests: Check for KVM nEPT support using "feature" MSRs
When checking for nEPT support in KVM, use kvm_get_feature_msr() instead
of vcpu_get_msr() to retrieve KVM's default TRUE_PROCBASED_CTLS and
PROCBASED_CTLS2 MSR values, i.e. don't require a VM+vCPU to query nEPT
support.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20220927165209.930904-1-dmatlack@google.com
[sean: rebase on merged code, write changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
David Matlack [Wed, 16 Nov 2022 20:46:31 +0000 (12:46 -0800)]
KVM: selftests: Assert in prepare_eptp() that nEPT is supported
Now that a VM isn't needed to check for nEPT support, assert that KVM
supports nEPT in prepare_eptp() instead of skipping the test, and push
the TEST_REQUIRE() check out to individual tests. The require+assert are
somewhat redundant and will incur some amount of ongoing maintenance
burden, but placing the "require" logic in the test makes it easier to
find/understand a test's requirements and in this case, provides a very
strong hint that the test cares about nEPT.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20220927165209.930904-1-dmatlack@google.com
[sean: rebase on merged code, write changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Sean Christopherson [Thu, 6 Oct 2022 00:51:25 +0000 (00:51 +0000)]
KVM: selftests: Drop helpers for getting specific KVM supported CPUID entry
Drop kvm_get_supported_cpuid_entry() and its inner helper now that all
known usage can use X86_FEATURE_*, X86_PROPERTY_*, X86_PMU_FEATURE_*, or
the dedicated Family/Model helpers. Providing "raw" access to CPUID
leafs is undesirable as it encourages open coding CPUID checks, which is
often error prone and not self-documenting.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-13-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:24 +0000 (00:51 +0000)]
KVM: selftests: Add and use KVM helpers for x86 Family and Model
Add KVM variants of the x86 Family and Model helpers, and use them in the
PMU event filter test. Open code the retrieval of KVM's supported CPUID
entry 0x1.0 in anticipation of dropping kvm_get_supported_cpuid_entry().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-12-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:23 +0000 (00:51 +0000)]
KVM: selftests: Add dedicated helpers for getting x86 Family and Model
Add dedicated helpers for getting x86's Family and Model, which are the
last holdouts that "need" raw access to CPUID information. FMS info is
a mess and requires not only splicing together multiple values, but
requires doing so conditional in the Family case.
Provide wrappers to reduce the odds of copy+paste errors, but mostly to
allow for the eventual removal of kvm_get_supported_cpuid_entry().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-11-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:22 +0000 (00:51 +0000)]
KVM: selftests: Add PMU feature framework, use in PMU event filter test
Add an X86_PMU_FEATURE_* framework to simplify probing architectural
events on Intel PMUs, which require checking the length of a bit vector
and the _absence_ of a "feature" bit. Add helpers for both KVM and
"this CPU", and use the newfangled magic (along with X86_PROPERTY_*)
to clean up pmu_event_filter_test.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-10-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:21 +0000 (00:51 +0000)]
KVM: selftests: Convert vmx_pmu_caps_test to use X86_PROPERTY_*
Add X86_PROPERTY_PMU_VERSION and use it in vmx_pmu_caps_test to replace
open coded versions of the same functionality.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-9-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:20 +0000 (00:51 +0000)]
KVM: selftests: Convert AMX test to use X86_PROPRETY_XXX
Add and use x86 "properties" for the myriad AMX CPUID values that are
validated by the AMX test. Drop most of the test's single-usage
helpers so that the asserts more precisely capture what check failed.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-8-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:19 +0000 (00:51 +0000)]
KVM: selftests: Add kvm_cpu_*() support for X86_PROPERTY_*
Extent X86_PROPERTY_* support to KVM, i.e. add kvm_cpu_property() and
kvm_cpu_has_p(), and use the new helpers in kvm_get_cpu_address_width().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-7-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:18 +0000 (00:51 +0000)]
KVM: selftests: Refactor kvm_cpuid_has() to prep for X86_PROPERTY_* support
Refactor kvm_cpuid_has() to prepare for extending X86_PROPERTY_* support
to KVM as well as "this CPU".
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-6-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:17 +0000 (00:51 +0000)]
KVM: selftests: Use X86_PROPERTY_MAX_KVM_LEAF in CPUID test
Use X86_PROPERTY_MAX_KVM_LEAF to replace the equivalent open coded check
on KVM's maximum paravirt CPUID leaf.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-5-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:16 +0000 (00:51 +0000)]
KVM: selftests: Add X86_PROPERTY_* framework to retrieve CPUID values
Introduce X86_PROPERTY_* to allow retrieving values/properties from CPUID
leafs, e.g. MAXPHYADDR from CPUID.0x80000008. Use the same core code as
X86_FEATURE_*, the primary difference is that properties are multi-bit
values, whereas features enumerate a single bit.
Add this_cpu_has_p() to allow querying whether or not a property exists
based on the maximum leaf associated with the property, e.g. MAXPHYADDR
doesn't exist if the max leaf for 0x8000_xxxx is less than 0x8000_0008.
Use the new property infrastructure in vm_compute_max_gfn() to prove
that the code works as intended. Future patches will convert additional
selftests code.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-4-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:15 +0000 (00:51 +0000)]
KVM: selftests: Refactor X86_FEATURE_* framework to prep for X86_PROPERTY_*
Refactor the X86_FEATURE_* framework to prepare for extending the core
logic to support "properties". The "feature" framework allows querying a
single CPUID bit to detect the presence of a feature; the "property"
framework will extend the idea to allow querying a value, i.e. to get a
value that is a set of contiguous bits in a CPUID leaf.
Opportunistically add static asserts to ensure features are fully defined
at compile time, and to try and catch mistakes in the definition of
features.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-3-seanjc@google.com
Sean Christopherson [Thu, 6 Oct 2022 00:51:14 +0000 (00:51 +0000)]
KVM: selftests: Add X86_FEATURE_PAE and use it calc "fallback" MAXPHYADDR
Add X86_FEATURE_PAE and use it to guesstimate the MAXPHYADDR when the
MAXPHYADDR CPUID entry isn't supported.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-2-seanjc@google.com
David Matlack [Wed, 2 Nov 2022 18:46:54 +0000 (11:46 -0700)]
KVM: selftests: Add a test for KVM_CAP_EXIT_ON_EMULATION_FAILURE
Add a selftest to exercise the KVM_CAP_EXIT_ON_EMULATION_FAILURE
capability.
This capability is also exercised through
smaller_maxphyaddr_emulation_test, but that test requires
allow_smaller_maxphyaddr=Y, which is off by default on Intel when ept=Y
and unconditionally disabled on AMD when npt=Y. This new test ensures
that KVM_CAP_EXIT_ON_EMULATION_FAILURE is exercised independent of
allow_smaller_maxphyaddr.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-11-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
David Matlack [Wed, 2 Nov 2022 18:46:53 +0000 (11:46 -0700)]
KVM: selftests: Expect #PF(RSVD) when TDP is disabled
Change smaller_maxphyaddr_emulation_test to expect a #PF(RSVD), rather
than an emulation failure, when TDP is disabled. KVM only needs to
emulate instructions to emulate a smaller guest.MAXPHYADDR when TDP is
enabled.
Fixes:
39bbcc3a4e39 ("selftests: kvm: Allows userspace to handle emulation errors.")
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-10-dmatlack@google.com
[sean: massage comment to talk about having to emulate due to MAXPHYADDR]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Sean Christopherson [Wed, 2 Nov 2022 18:46:52 +0000 (11:46 -0700)]
KVM: selftests: Provide error code as a KVM_ASM_SAFE() output
Provide the error code on a fault in KVM_ASM_SAFE(), e.g. to allow tests
to assert that #PF generates the correct error code without needing to
manually install a #PF handler. Use r10 as the scratch register for the
error code, as it's already clobbered by the asm blob (loaded with the
RIP of the to-be-executed instruction). Deliberately load the output
"error_code" even in the non-faulting path so that error_code is always
initialized with deterministic data (the aforementioned RIP), i.e to
ensure a selftest won't end up with uninitialized consumption regardless
of how KVM_ASM_SAFE() is used.
Don't clear r10 in the non-faulting case and instead load error code with
the RIP (see above). The error code is valid if and only if an exception
occurs, and '0' isn't necessarily a better "invalid" value, e.g. '0'
could result in false passes for a buggy test.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-9-dmatlack@google.com
Sean Christopherson [Wed, 2 Nov 2022 18:46:51 +0000 (11:46 -0700)]
KVM: selftests: Avoid JMP in non-faulting path of KVM_ASM_SAFE()
Clear R9 in the non-faulting path of KVM_ASM_SAFE() and fall through to
to a common load of "vector" to effectively load "vector" with '0' to
reduce the code footprint of the asm blob, to reduce the runtime overhead
of the non-faulting path (when "vector" is stored in a register), and so
that additional output constraints that are valid if and only if a fault
occur are loaded even in the non-faulting case.
A future patch will add a 64-bit output for the error code, and if its
output is not explicitly loaded with _something_, the user of the asm
blob can end up technically consuming uninitialized data. Using a
common path to load the output constraints will allow using an existing
scratch register, e.g. r10, to hold the error code in the faulting path,
while also guaranteeing the error code is initialized with deterministic
data in the non-faulting patch (r10 is loaded with the RIP of
to-be-executed instruction).
Consuming the error code when a fault doesn't occur would obviously be a
test bug, but there's no guarantee the compiler will detect uninitialized
consumption. And conversely, it's theoretically possible that the
compiler might throw a false positive on uninitialized data, e.g. if the
compiler can't determine that the non-faulting path won't touch the error
code.
Alternatively, the error code could be explicitly loaded in the
non-faulting path, but loading a 64-bit memory|register output operand
with an explicitl value requires a sign-extended "MOV imm32, r/m64",
which isn't exactly straightforward and has a largish code footprint.
And loading the error code with what is effectively garbage (from a
scratch register) avoids having to choose an arbitrary value for the
non-faulting case.
Opportunistically remove a rogue asterisk in the block comment.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-8-dmatlack@google.com
David Matlack [Wed, 2 Nov 2022 18:46:50 +0000 (11:46 -0700)]
KVM: selftests: Copy KVM PFERR masks into selftests
Copy KVM's macros for page fault error masks into processor.h so they
can be used in selftests.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-7-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
David Matlack [Wed, 2 Nov 2022 18:46:49 +0000 (11:46 -0700)]
KVM: x86/mmu: Use BIT{,_ULL}() for PFERR masks
Use the preferred BIT() and BIT_ULL() to construct the PFERR masks
rather than open-coding the bit shifting.
No functional change intended.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-6-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
David Matlack [Wed, 2 Nov 2022 18:46:48 +0000 (11:46 -0700)]
KVM: selftests: Move flds instruction emulation failure handling to header
Move the flds instruction emulation failure handling code to a header
so it can be re-used in an upcoming test.
No functional change intended.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-5-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
David Matlack [Wed, 2 Nov 2022 18:46:47 +0000 (11:46 -0700)]
KVM: selftests: Delete dead ucall code
Delete a bunch of code related to ucall handling from
smaller_maxphyaddr_emulation_test. The only thing
smaller_maxphyaddr_emulation_test needs to check is that the vCPU exits
with UCALL_DONE after the second vcpu_run().
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-4-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
David Matlack [Wed, 2 Nov 2022 18:46:46 +0000 (11:46 -0700)]
KVM: selftests: Explicitly require instructions bytes
Hard-code the flds instruction and assert the exact instruction bytes
are present in run->emulation_failure. The test already requires the
instruction bytes to be present because that's the only way the test
will advance the RIP past the flds and get to GUEST_DONE().
Note that KVM does not necessarily return exactly 2 bytes in
run->emulation_failure since it may not know the exact instruction
length in all cases. So just assert that
run->emulation_failure.insn_size is at least 2.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-3-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
David Matlack [Wed, 2 Nov 2022 18:46:45 +0000 (11:46 -0700)]
KVM: selftests: Rename emulator_error_test to smaller_maxphyaddr_emulation_test
Rename emulator_error_test to smaller_maxphyaddr_emulation_test and
update the comment at the top of the file to document that this is
explicitly a test to validate that KVM emulates instructions in response
to an EPT violation when emulating a smaller MAXPHYADDR.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-2-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Gautam Menghani [Mon, 17 Oct 2022 17:58:19 +0000 (23:28 +0530)]
KVM: selftests: Don't assume vcpu->id is '0' in xAPIC state test
In xapic_state_test's test_icr(), explicitly skip iterations that would
match vcpu->id instead of assuming vcpu->id is '0', so that IPIs are
are correctly sent to non-existent vCPUs.
Suggested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/kvm/YyoZr9rXSSMEtdh5@google.com
Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Link: https://lore.kernel.org/r/20221017175819.12672-1-gautammenghani201@gmail.com
[sean: massage shortlog and changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Vishal Annapurve [Tue, 15 Nov 2022 21:38:45 +0000 (21:38 +0000)]
KVM: selftests: Add arch specific post vm creation hook
Add arch specific API kvm_arch_vm_post_create to perform any required setup
after VM creation.
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
Link: https://lore.kernel.org/r/20221115213845.3348210-4-vannapurve@google.com
[sean: place x86's implementation by vm_arch_vcpu_add()]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Vishal Annapurve [Tue, 15 Nov 2022 21:38:44 +0000 (21:38 +0000)]
KVM: selftests: Add arch specific initialization
Introduce arch specific API: kvm_selftest_arch_init to allow each arch to
handle initialization before running any selftest logic.
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
Link: https://lore.kernel.org/r/20221115213845.3348210-3-vannapurve@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>