Re: [PATCH v7 09/26] KVM: x86: Rename kvm_{g,s}et_msr() to menifest emulation operations

From: Maxim Levitsky
Date: Thu Nov 30 2023 - 12:47:25 EST


On Fri, 2023-11-24 at 00:53 -0500, Yang Weijiang wrote:
> Rename kvm_{g,s}et_msr() to kvm_emulate_msr_{read,write}() to make it
> more obvious that KVM uses these helpers to emulate guest behaviors,
> i.e., host_initiated == false in these helpers.
>
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
> ---
> arch/x86/include/asm/kvm_host.h | 4 ++--
> arch/x86/kvm/smm.c | 4 ++--
> arch/x86/kvm/vmx/nested.c | 13 +++++++------
> arch/x86/kvm/x86.c | 10 +++++-----
> 4 files changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index d7036982332e..5cfa18aaf33f 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1967,8 +1967,8 @@ void kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu);
> void kvm_enable_efer_bits(u64);
> bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer);
> int __kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data, bool host_initiated);
> -int kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data);
> -int kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data);
> +int kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data);
> +int kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data);
> int kvm_emulate_rdmsr(struct kvm_vcpu *vcpu);
> int kvm_emulate_wrmsr(struct kvm_vcpu *vcpu);
> int kvm_emulate_as_nop(struct kvm_vcpu *vcpu);
> diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c
> index dc3d95fdca7d..45c855389ea7 100644
> --- a/arch/x86/kvm/smm.c
> +++ b/arch/x86/kvm/smm.c
> @@ -535,7 +535,7 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt,
>
> vcpu->arch.smbase = smstate->smbase;
>
> - if (kvm_set_msr(vcpu, MSR_EFER, smstate->efer & ~EFER_LMA))
> + if (kvm_emulate_msr_write(vcpu, MSR_EFER, smstate->efer & ~EFER_LMA))
> return X86EMUL_UNHANDLEABLE;
>
> rsm_load_seg_64(vcpu, &smstate->tr, VCPU_SREG_TR);
> @@ -626,7 +626,7 @@ int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
>
> /* And finally go back to 32-bit mode. */
> efer = 0;
> - kvm_set_msr(vcpu, MSR_EFER, efer);
> + kvm_emulate_msr_write(vcpu, MSR_EFER, efer);
> }
> #endif
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index c5ec0ef51ff7..2034337681f9 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -927,7 +927,7 @@ static u32 nested_vmx_load_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count)
> __func__, i, e.index, e.reserved);
> goto fail;
> }
> - if (kvm_set_msr(vcpu, e.index, e.value)) {
> + if (kvm_emulate_msr_write(vcpu, e.index, e.value)) {
> pr_debug_ratelimited(
> "%s cannot write MSR (%u, 0x%x, 0x%llx)\n",
> __func__, i, e.index, e.value);
> @@ -963,7 +963,7 @@ static bool nested_vmx_get_vmexit_msr_value(struct kvm_vcpu *vcpu,
> }
> }
>
> - if (kvm_get_msr(vcpu, msr_index, data)) {
> + if (kvm_emulate_msr_read(vcpu, msr_index, data)) {
> pr_debug_ratelimited("%s cannot read MSR (0x%x)\n", __func__,
> msr_index);
> return false;
> @@ -2649,7 +2649,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
>
> if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL) &&
> kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu)) &&
> - WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
> + WARN_ON_ONCE(kvm_emulate_msr_write(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
> vmcs12->guest_ia32_perf_global_ctrl))) {
> *entry_failure_code = ENTRY_FAIL_DEFAULT;
> return -EINVAL;
> @@ -4524,8 +4524,9 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
> }
> if ((vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL) &&
> kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu)))
> - WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
> - vmcs12->host_ia32_perf_global_ctrl));
> + WARN_ON_ONCE(kvm_emulate_msr_write(vcpu,
> + MSR_CORE_PERF_GLOBAL_CTRL,
> + vmcs12->host_ia32_perf_global_ctrl));
>
> /* Set L1 segment info according to Intel SDM
> 27.5.2 Loading Host Segment and Descriptor-Table Registers */
> @@ -4700,7 +4701,7 @@ static void nested_vmx_restore_host_state(struct kvm_vcpu *vcpu)
> goto vmabort;
> }
>
> - if (kvm_set_msr(vcpu, h.index, h.value)) {
> + if (kvm_emulate_msr_write(vcpu, h.index, h.value)) {
> pr_debug_ratelimited(
> "%s WRMSR failed (%u, 0x%x, 0x%llx)\n",
> __func__, j, h.index, h.value);
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 2c924075f6f1..b9c2c0cd4cf5 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1973,17 +1973,17 @@ static int kvm_set_msr_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 data)
> return kvm_set_msr_ignored_check(vcpu, index, data, false);
> }
>
> -int kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data)
> +int kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data)
> {
> return kvm_get_msr_ignored_check(vcpu, index, data, false);
> }
> -EXPORT_SYMBOL_GPL(kvm_get_msr);
> +EXPORT_SYMBOL_GPL(kvm_emulate_msr_read);
>
> -int kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data)
> +int kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data)
> {
> return kvm_set_msr_ignored_check(vcpu, index, data, false);
> }
> -EXPORT_SYMBOL_GPL(kvm_set_msr);
> +EXPORT_SYMBOL_GPL(kvm_emulate_msr_write);
>
> static void complete_userspace_rdmsr(struct kvm_vcpu *vcpu)
> {
> @@ -8329,7 +8329,7 @@ static int emulator_set_msr_with_filter(struct x86_emulate_ctxt *ctxt,
> static int emulator_get_msr(struct x86_emulate_ctxt *ctxt,
> u32 msr_index, u64 *pdata)
> {
> - return kvm_get_msr(emul_to_vcpu(ctxt), msr_index, pdata);
> + return kvm_emulate_msr_read(emul_to_vcpu(ctxt), msr_index, pdata);
> }
>
> static int emulator_check_pmc(struct x86_emulate_ctxt *ctxt,

Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>

Best regards,
Maxim Levitsky