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Commit 8065dbd1 authored by Sean Christopherson's avatar Sean Christopherson Committed by Radim Krčmář
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KVM: x86: Invert emulation re-execute behavior to make it opt-in 



Re-execution of an instruction after emulation decode failure is
intended to be used only when emulating shadow page accesses.  Invert
the flag to make allowing re-execution opt-in since that behavior is
by far in the minority.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent 35be0ade

arch/x86/include/asm/kvm_host.h

+3 −5
Original line number Original line Diff line number Diff line
@@ -1238,7 +1238,7 @@ enum emulation_result { 
#define EMULTYPE_TRAP_UD	    (1 << 1)

#define EMULTYPE_TRAP_UD	    (1 << 1)

#define EMULTYPE_SKIP		    (1 << 2)

#define EMULTYPE_SKIP		    (1 << 2)

#define EMULTYPE_RETRY		    (1 << 3)

#define EMULTYPE_RETRY		    (1 << 3)

#define EMULTYPE_NO_REEXECUTE	    (1 << 4)

#define EMULTYPE_ALLOW_REEXECUTE    (1 << 4)

#define EMULTYPE_NO_UD_ON_FAIL	    (1 << 5)

#define EMULTYPE_NO_UD_ON_FAIL	    (1 << 5)

#define EMULTYPE_VMWARE		    (1 << 6)

#define EMULTYPE_VMWARE		    (1 << 6)

int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2,

int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2,
@@ -1247,15 +1247,13 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, 
static inline int emulate_instruction(struct kvm_vcpu *vcpu,

static inline int emulate_instruction(struct kvm_vcpu *vcpu,

			int emulation_type)

			int emulation_type)

{

{

	return x86_emulate_instruction(vcpu, 0,

	return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0);

			emulation_type | EMULTYPE_NO_REEXECUTE, NULL, 0);

}

}





static inline int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,

static inline int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,

						      void *insn, int insn_len)

						      void *insn, int insn_len)

{

{

	return x86_emulate_instruction(vcpu, 0, EMULTYPE_NO_REEXECUTE,

	return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len);

				       insn, insn_len);

}

}





void kvm_enable_efer_bits(u64);

void kvm_enable_efer_bits(u64);

arch/x86/kvm/mmu.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -5217,7 +5217,7 @@ static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 
int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code,

int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code,

		       void *insn, int insn_len)

		       void *insn, int insn_len)

{

{

	int r, emulation_type = EMULTYPE_RETRY;

	int r, emulation_type = EMULTYPE_RETRY | EMULTYPE_ALLOW_REEXECUTE;

	enum emulation_result er;

	enum emulation_result er;

	bool direct = vcpu->arch.mmu.direct_map;

	bool direct = vcpu->arch.mmu.direct_map;

arch/x86/kvm/x86.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -5870,7 +5870,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t cr2, 
	gpa_t gpa = cr2;

	gpa_t gpa = cr2;

	kvm_pfn_t pfn;

	kvm_pfn_t pfn;





	if (emulation_type & EMULTYPE_NO_REEXECUTE)

	if (!(emulation_type & EMULTYPE_ALLOW_REEXECUTE))

		return false;

		return false;





	if (!vcpu->arch.mmu.direct_map) {

	if (!vcpu->arch.mmu.direct_map) {