From f422f853af0369be27d2a9f1b20079f2bc3d1ca2 Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Fri, 6 Jan 2023 10:36:00 +0000 Subject: [PATCH] KVM: x86/xen: update Xen CPUID Leaf 4 (tsc info) sub-leaves, if present The scaling information in subleaf 1 should match the values set by KVM in the 'vcpu_info' sub-structure 'time_info' (a.k.a. pvclock_vcpu_time_info) which is shared with the guest, but is not directly available to the VMM. The offset values are not set since a TSC offset is already applied. The TSC frequency should also be set in sub-leaf 2. Signed-off-by: Paul Durrant Reviewed-by: David Woodhouse Link: https://lore.kernel.org/r/20230106103600.528-3-pdurrant@amazon.com Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/asm/xen/hypervisor.h | 4 +++- arch/x86/kvm/cpuid.c | 2 ++ arch/x86/kvm/x86.c | 1 + arch/x86/kvm/xen.c | 26 ++++++++++++++++++++++++++ arch/x86/kvm/xen.h | 7 +++++++ 6 files changed, 40 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 0e5da33..8b38a4c 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -703,6 +703,7 @@ struct kvm_vcpu_xen { struct hrtimer timer; int poll_evtchn; struct timer_list poll_timer; + struct kvm_hypervisor_cpuid cpuid; }; struct kvm_queued_exception { diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h index 16f548a..5fc35f8 100644 --- a/arch/x86/include/asm/xen/hypervisor.h +++ b/arch/x86/include/asm/xen/hypervisor.h @@ -38,9 +38,11 @@ extern struct start_info *xen_start_info; #include +#define XEN_SIGNATURE "XenVMMXenVMM" + static inline uint32_t xen_cpuid_base(void) { - return hypervisor_cpuid_base("XenVMMXenVMM", 2); + return hypervisor_cpuid_base(XEN_SIGNATURE, 2); } struct pci_dev; diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index c5c6eef..8f8edea 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -26,6 +26,7 @@ #include "mmu.h" #include "trace.h" #include "pmu.h" +#include "xen.h" /* * Unlike "struct cpuinfo_x86.x86_capability", kvm_cpu_caps doesn't need to be @@ -443,6 +444,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, vcpu->arch.cpuid_nent = nent; vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE); + vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE); kvm_vcpu_after_set_cpuid(vcpu); return 0; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fc3ae3c..65b401e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3161,6 +3161,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) &vcpu->hv_clock.tsc_shift, &vcpu->hv_clock.tsc_to_system_mul); vcpu->hw_tsc_khz = tgt_tsc_khz; + kvm_xen_update_tsc_info(v); } vcpu->hv_clock.tsc_timestamp = tsc_timestamp; diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 2681e20..40edf4d 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -23,6 +23,9 @@ #include #include +#include + +#include "cpuid.h" #include "trace.h" static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm); @@ -2077,6 +2080,29 @@ void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu) del_timer_sync(&vcpu->arch.xen.poll_timer); } +void kvm_xen_update_tsc_info(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *entry; + u32 function; + + if (!vcpu->arch.xen.cpuid.base) + return; + + function = vcpu->arch.xen.cpuid.base | XEN_CPUID_LEAF(3); + if (function > vcpu->arch.xen.cpuid.limit) + return; + + entry = kvm_find_cpuid_entry_index(vcpu, function, 1); + if (entry) { + entry->ecx = vcpu->arch.hv_clock.tsc_to_system_mul; + entry->edx = vcpu->arch.hv_clock.tsc_shift; + } + + entry = kvm_find_cpuid_entry_index(vcpu, function, 2); + if (entry) + entry->eax = vcpu->arch.hw_tsc_khz; +} + void kvm_xen_init_vm(struct kvm *kvm) { mutex_init(&kvm->arch.xen.xen_lock); diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h index ea33d80..f8f1fe2 100644 --- a/arch/x86/kvm/xen.h +++ b/arch/x86/kvm/xen.h @@ -9,6 +9,8 @@ #ifndef __ARCH_X86_KVM_XEN_H__ #define __ARCH_X86_KVM_XEN_H__ +#include + #ifdef CONFIG_KVM_XEN #include @@ -32,6 +34,7 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, int kvm_xen_setup_evtchn(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e, const struct kvm_irq_routing_entry *ue); +void kvm_xen_update_tsc_info(struct kvm_vcpu *vcpu); static inline bool kvm_xen_msr_enabled(struct kvm *kvm) { @@ -135,6 +138,10 @@ static inline bool kvm_xen_timer_enabled(struct kvm_vcpu *vcpu) { return false; } + +static inline void kvm_xen_update_tsc_info(struct kvm_vcpu *vcpu) +{ +} #endif int kvm_xen_hypercall(struct kvm_vcpu *vcpu); -- 2.7.4