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SubjectRe: [PATCH 5/9] KVM: x86: Pass emulation type to can_emulate_instruction()
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On 20/01/2022 01:07, Sean Christopherson wrote:
> Pass the emulation type to kvm_x86_ops.can_emulate_insutrction() so that

typo in function name - should be can_emulate_instruction()

> a future commit can harden KVM's SEV support to WARN on emulation
> scenarios that should never happen.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>


Reviewed-by: Liam Merwick <liam.merwick@oracle.com>


> ---
> arch/x86/include/asm/kvm_host.h | 3 ++-
> arch/x86/kvm/svm/svm.c | 3 ++-
> arch/x86/kvm/vmx/vmx.c | 7 ++++---
> arch/x86/kvm/x86.c | 11 +++++++++--
> 4 files changed, 17 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 682ad02a4e58..c890931c9c65 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1482,7 +1482,8 @@ struct kvm_x86_ops {
>
> int (*get_msr_feature)(struct kvm_msr_entry *entry);
>
> - bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, void *insn, int insn_len);
> + bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, int emul_type,
> + void *insn, int insn_len);
>
> bool (*apic_init_signal_blocked)(struct kvm_vcpu *vcpu);
> int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index edea52be6c01..994224ae2731 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -4257,7 +4257,8 @@ static void svm_enable_smi_window(struct kvm_vcpu *vcpu)
> }
> }
>
> -static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)
> +static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
> + void *insn, int insn_len)
> {
> bool smep, smap, is_user;
> unsigned long cr4;
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index a02a28ce7cc3..4b4c1dfa6842 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -1487,11 +1487,12 @@ static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data)
> return 0;
> }
>
> -static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)
> +static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
> + void *insn, int insn_len)
> {
> /*
> * Emulation of instructions in SGX enclaves is impossible as RIP does
> - * not point tthe failing instruction, and even if it did, the code
> + * not point at the failing instruction, and even if it did, the code
> * stream is inaccessible. Inject #UD instead of exiting to userspace
> * so that guest userspace can't DoS the guest simply by triggering
> * emulation (enclaves are CPL3 only).
> @@ -5397,7 +5398,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
> {
> gpa_t gpa;
>
> - if (!vmx_can_emulate_instruction(vcpu, NULL, 0))
> + if (!vmx_can_emulate_instruction(vcpu, EMULTYPE_PF, NULL, 0))
> return 1;
>
> /*
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 55518b7d3b96..2fa4687de8e4 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6810,6 +6810,13 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
> }
> EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
>
> +static int kvm_can_emulate_insn(struct kvm_vcpu *vcpu, int emul_type,
> + void *insn, int insn_len)
> +{
> + return static_call(kvm_x86_can_emulate_instruction)(vcpu, emul_type,
> + insn, insn_len);
> +}
> +
> int handle_ud(struct kvm_vcpu *vcpu)
> {
> static const char kvm_emulate_prefix[] = { __KVM_EMULATE_PREFIX };
> @@ -6817,7 +6824,7 @@ int handle_ud(struct kvm_vcpu *vcpu)
> char sig[5]; /* ud2; .ascii "kvm" */
> struct x86_exception e;
>
> - if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, NULL, 0)))
> + if (unlikely(!kvm_can_emulate_insn(vcpu, emul_type, NULL, 0)))
> return 1;
>
> if (force_emulation_prefix &&
> @@ -8193,7 +8200,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
> bool writeback = true;
> bool write_fault_to_spt;
>
> - if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, insn, insn_len)))
> + if (unlikely(!kvm_can_emulate_insn(vcpu, emulation_type, insn, insn_len)))
> return 1;
>
> vcpu->arch.l1tf_flush_l1d = true;

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