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From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Brijesh Singh <brijesh.singh@amd.com>,
	Liam Merwick <liam.merwick@oracle.com>
Subject: [PATCH 5/9] KVM: x86: Pass emulation type to can_emulate_instruction()
Date: Thu, 20 Jan 2022 01:07:15 +0000	[thread overview]
Message-ID: <20220120010719.711476-6-seanjc@google.com> (raw)
In-Reply-To: <20220120010719.711476-1-seanjc@google.com>

Pass the emulation type to kvm_x86_ops.can_emulate_insutrction() so that
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>
---
 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;
-- 
2.34.1.703.g22d0c6ccf7-goog


  parent reply	other threads:[~2022-01-20  1:08 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-20  1:07 [PATCH 0/9] KVM: SVM: Fix and clean up "can emulate" mess Sean Christopherson
2022-01-20  1:07 ` [PATCH 1/9] KVM: SVM: Never reject emulation due to SMAP errata for !SEV guests Sean Christopherson
2022-01-20 14:16   ` Liam Merwick
2022-01-20  1:07 ` [PATCH 2/9] Revert "KVM: SVM: avoid infinite loop on NPF from bad address" Sean Christopherson
2022-01-20 14:17   ` Liam Merwick
2022-01-20  1:07 ` [PATCH 3/9] KVM: SVM: Don't intercept #GP for SEV guests Sean Christopherson
2022-01-20 14:30   ` Liam Merwick
2022-01-20 16:55     ` Sean Christopherson
2022-01-20  1:07 ` [PATCH 4/9] KVM: SVM: Explicitly require DECODEASSISTS to enable SEV support Sean Christopherson
2022-01-20 14:32   ` Liam Merwick
2022-01-20  1:07 ` Sean Christopherson [this message]
2022-01-20 14:38   ` [PATCH 5/9] KVM: x86: Pass emulation type to can_emulate_instruction() Liam Merwick
2022-01-20  1:07 ` [PATCH 6/9] KVM: SVM: WARN if KVM attempts emulation on #UD or #GP for SEV guests Sean Christopherson
2022-01-20 15:44   ` Liam Merwick
2022-01-20 17:04     ` Sean Christopherson
2022-01-25 14:56       ` Paolo Bonzini
2022-01-20  1:07 ` [PATCH 7/9] KVM: SVM: Inject #UD on attempted emulation for SEV guest w/o insn buffer Sean Christopherson
2022-01-20 16:11   ` Liam Merwick
2022-01-20  1:07 ` [PATCH 8/9] KVM: SVM: Don't apply SEV+SMAP workaround on code fetch or PT access Sean Christopherson
2022-01-20 16:37   ` Liam Merwick
2022-01-20  1:07 ` [PATCH 9/9] KVM: SVM: Don't kill SEV guest if SMAP erratum triggers in usermode Sean Christopherson
2022-01-20 16:46   ` Liam Merwick
2022-01-20 16:58 ` [PATCH 0/9] KVM: SVM: Fix and clean up "can emulate" mess Liam Merwick
2022-01-21  8:30   ` Liam Merwick
2022-01-25 14:52 ` Paolo Bonzini

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