From 5fde25284dfe9d3f12afdceec410cddb8d4b889a Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 14 Jun 2022 23:16:12 +0200 Subject: [PATCH] KVM: VMX: Convert launched argument to flags commit bb06650634d3552c0f8557e9d16aa1a408040e28 upstream. Convert __vmx_vcpu_run()'s 'launched' argument to 'flags', in preparation for doing SPEC_CTRL handling immediately after vmexit, which will need another flag. This is much easier than adding a fourth argument, because this code supports both 32-bit and 64-bit, and the fourth argument on 32-bit would have to be pushed on the stack. Note that __vmx_vcpu_run_flags() is called outside of the noinstr critical section because it will soon start calling potentially traceable functions. Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx/nested.c | 2 +- arch/x86/kvm/vmx/run_flags.h | 7 +++++++ arch/x86/kvm/vmx/vmenter.S | 9 +++++---- arch/x86/kvm/vmx/vmx.c | 17 ++++++++++++++--- arch/x86/kvm/vmx/vmx.h | 5 ++++- 5 files changed, 31 insertions(+), 9 deletions(-) create mode 100644 arch/x86/kvm/vmx/run_flags.h diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f7bdb62..5f91aa6 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3077,7 +3077,7 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) } vm_fail = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs, - vmx->loaded_vmcs->launched); + __vmx_vcpu_run_flags(vmx)); if (vmx->msr_autoload.host.nr) vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr); diff --git a/arch/x86/kvm/vmx/run_flags.h b/arch/x86/kvm/vmx/run_flags.h new file mode 100644 index 0000000..57f4c66 --- /dev/null +++ b/arch/x86/kvm/vmx/run_flags.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __KVM_X86_VMX_RUN_FLAGS_H +#define __KVM_X86_VMX_RUN_FLAGS_H + +#define VMX_RUN_VMRESUME (1 << 0) + +#endif /* __KVM_X86_VMX_RUN_FLAGS_H */ diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index cd1cd51..95d3a47 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -5,6 +5,7 @@ #include #include #include +#include "run_flags.h" #define WORD_SIZE (BITS_PER_LONG / 8) @@ -34,7 +35,7 @@ * __vmx_vcpu_run - Run a vCPU via a transition to VMX guest mode * @vmx: struct vcpu_vmx * (forwarded to vmx_update_host_rsp) * @regs: unsigned long * (to guest registers) - * @launched: %true if the VMCS has been launched + * @flags: VMX_RUN_VMRESUME: use VMRESUME instead of VMLAUNCH * * Returns: * 0 on VM-Exit, 1 on VM-Fail @@ -59,7 +60,7 @@ SYM_FUNC_START(__vmx_vcpu_run) */ push %_ASM_ARG2 - /* Copy @launched to BL, _ASM_ARG3 is volatile. */ + /* Copy @flags to BL, _ASM_ARG3 is volatile. */ mov %_ASM_ARG3B, %bl lea (%_ASM_SP), %_ASM_ARG2 @@ -69,7 +70,7 @@ SYM_FUNC_START(__vmx_vcpu_run) mov (%_ASM_SP), %_ASM_AX /* Check if vmlaunch or vmresume is needed */ - testb %bl, %bl + testb $VMX_RUN_VMRESUME, %bl /* Load guest registers. Don't clobber flags. */ mov VCPU_RCX(%_ASM_AX), %_ASM_CX @@ -92,7 +93,7 @@ SYM_FUNC_START(__vmx_vcpu_run) mov VCPU_RAX(%_ASM_AX), %_ASM_AX /* Check EFLAGS.ZF from 'testb' above */ - je .Lvmlaunch + jz .Lvmlaunch /* * After a successful VMRESUME/VMLAUNCH, control flow "magically" diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 54724f5..bac08c26 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -835,6 +835,16 @@ static bool msr_write_intercepted(struct vcpu_vmx *vmx, u32 msr) MSR_IA32_SPEC_CTRL); } +unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx) +{ + unsigned int flags = 0; + + if (vmx->loaded_vmcs->launched) + flags |= VMX_RUN_VMRESUME; + + return flags; +} + static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx, unsigned long entry, unsigned long exit) { @@ -6667,7 +6677,8 @@ static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu) } static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, - struct vcpu_vmx *vmx) + struct vcpu_vmx *vmx, + unsigned long flags) { kvm_guest_enter_irqoff(); @@ -6686,7 +6697,7 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, native_write_cr2(vcpu->arch.cr2); vmx->fail = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs, - vmx->loaded_vmcs->launched); + flags); vcpu->arch.cr2 = native_read_cr2(); @@ -6786,7 +6797,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu) x86_spec_ctrl_set_guest(vmx->spec_ctrl, 0); /* The actual VMENTER/EXIT is in the .noinstr.text section. */ - vmx_vcpu_enter_exit(vcpu, vmx); + vmx_vcpu_enter_exit(vcpu, vmx, __vmx_vcpu_run_flags(vmx)); /* * We do not use IBRS in the kernel. If this vCPU has used the diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 12fe7b3..3547611 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -13,6 +13,7 @@ #include "vmcs.h" #include "vmx_ops.h" #include "cpuid.h" +#include "run_flags.h" #define MSR_TYPE_R 1 #define MSR_TYPE_W 2 @@ -382,7 +383,9 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu); struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr); void pt_update_intercept_for_msr(struct kvm_vcpu *vcpu); void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp); -bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched); +unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx); +bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, + unsigned int flags); int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr); void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu); -- 2.7.4