From: Sean Christopherson Date: Thu, 23 Aug 2018 20:56:47 +0000 (-0700) Subject: KVM: x86: SVM: Set EMULTYPE_NO_REEXECUTE for RSM emulation X-Git-Tag: v4.19-rc3~7^2~18 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=35be0aded76b54a24dc8aa678a71bca22273e8d8;p=thirdparty%2Fkernel%2Flinux.git KVM: x86: SVM: Set EMULTYPE_NO_REEXECUTE for RSM emulation Re-execution after an emulation decode failure is only intended to handle a case where two or vCPUs race to write a shadowed page, i.e. we should never re-execute an instruction as part of RSM emulation. Add a new helper, kvm_emulate_instruction_from_buffer(), to support emulating from a pre-defined buffer. This eliminates the last direct call to x86_emulate_instruction() outside of kvm_mmu_page_fault(), which means x86_emulate_instruction() can be unexported in a future patch. Fixes: 7607b7174405 ("KVM: SVM: install RSM intercept") Cc: Brijesh Singh Signed-off-by: Sean Christopherson Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář --- diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 00ddb0c9e612a..3b220b86c8e48 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1251,6 +1251,13 @@ static inline int emulate_instruction(struct kvm_vcpu *vcpu, emulation_type | EMULTYPE_NO_REEXECUTE, NULL, 0); } +static inline int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, + void *insn, int insn_len) +{ + return x86_emulate_instruction(vcpu, 0, EMULTYPE_NO_REEXECUTE, + insn, insn_len); +} + void kvm_enable_efer_bits(u64); bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer); int kvm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 4339fc4715fa9..b3cdfde8ff5e4 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3874,8 +3874,8 @@ static int emulate_on_interception(struct vcpu_svm *svm) static int rsm_interception(struct vcpu_svm *svm) { - return x86_emulate_instruction(&svm->vcpu, 0, 0, - rsm_ins_bytes, 2) == EMULATE_DONE; + return kvm_emulate_instruction_from_buffer(&svm->vcpu, + rsm_ins_bytes, 2) == EMULATE_DONE; } static int rdpmc_interception(struct vcpu_svm *svm)