KVM: SVM: limit kvm_handle_page_fault to #PF handling

It has always annoyed me a bit how SVM_EXIT_NPF is handled by
pf_interception.  This is also the only reason behind the
under-documented need_unprotect argument to kvm_handle_page_fault.
Let NPF go straight to kvm_mmu_page_fault, just like VMX
does in handle_ept_violation and handle_ept_misconfig.

Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2017-08-11 18:36:43 +02:00
parent 1cf53587c0
commit d000653057
4 changed files with 17 additions and 9 deletions

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@ -3820,8 +3820,7 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
} }
int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
u64 fault_address, char *insn, int insn_len, u64 fault_address, char *insn, int insn_len)
bool need_unprotect)
{ {
int r = 1; int r = 1;
@ -3829,7 +3828,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
default: default:
trace_kvm_page_fault(fault_address, error_code); trace_kvm_page_fault(fault_address, error_code);
if (need_unprotect && kvm_event_needs_reinjection(vcpu)) if (kvm_event_needs_reinjection(vcpu))
kvm_mmu_unprotect_page_virt(vcpu, fault_address); kvm_mmu_unprotect_page_virt(vcpu, fault_address);
r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn,
insn_len); insn_len);

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@ -65,8 +65,7 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
bool accessed_dirty); bool accessed_dirty);
bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu); bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
u64 fault_address, char *insn, int insn_len, u64 fault_address, char *insn, int insn_len);
bool need_unprotect);
static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm) static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm)
{ {

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@ -2141,7 +2141,18 @@ static int pf_interception(struct vcpu_svm *svm)
return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address, return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address,
svm->vmcb->control.insn_bytes, svm->vmcb->control.insn_bytes,
svm->vmcb->control.insn_len, !npt_enabled); svm->vmcb->control.insn_len);
}
static int npf_interception(struct vcpu_svm *svm)
{
u64 fault_address = svm->vmcb->control.exit_info_2;
u64 error_code = svm->vmcb->control.exit_info_1;
trace_kvm_page_fault(fault_address, error_code);
return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code,
svm->vmcb->control.insn_bytes,
svm->vmcb->control.insn_len);
} }
static int db_interception(struct vcpu_svm *svm) static int db_interception(struct vcpu_svm *svm)
@ -4128,7 +4139,7 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
[SVM_EXIT_MONITOR] = monitor_interception, [SVM_EXIT_MONITOR] = monitor_interception,
[SVM_EXIT_MWAIT] = mwait_interception, [SVM_EXIT_MWAIT] = mwait_interception,
[SVM_EXIT_XSETBV] = xsetbv_interception, [SVM_EXIT_XSETBV] = xsetbv_interception,
[SVM_EXIT_NPF] = pf_interception, [SVM_EXIT_NPF] = npf_interception,
[SVM_EXIT_RSM] = emulate_on_interception, [SVM_EXIT_RSM] = emulate_on_interception,
[SVM_EXIT_AVIC_INCOMPLETE_IPI] = avic_incomplete_ipi_interception, [SVM_EXIT_AVIC_INCOMPLETE_IPI] = avic_incomplete_ipi_interception,
[SVM_EXIT_AVIC_UNACCELERATED_ACCESS] = avic_unaccelerated_access_interception, [SVM_EXIT_AVIC_UNACCELERATED_ACCESS] = avic_unaccelerated_access_interception,

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@ -5894,8 +5894,7 @@ static int handle_exception(struct kvm_vcpu *vcpu)
cr2 = vmcs_readl(EXIT_QUALIFICATION); cr2 = vmcs_readl(EXIT_QUALIFICATION);
/* EPT won't cause page fault directly */ /* EPT won't cause page fault directly */
WARN_ON_ONCE(!vcpu->arch.apf.host_apf_reason && enable_ept); WARN_ON_ONCE(!vcpu->arch.apf.host_apf_reason && enable_ept);
return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0, return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0);
true);
} }
ex_no = intr_info & INTR_INFO_VECTOR_MASK; ex_no = intr_info & INTR_INFO_VECTOR_MASK;