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From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Maxim Levitsky <mlevitsk@redhat.com>,
	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>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	linux-kernel@vger.kernel.org,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>
Subject: [PATCH v5 7/7] nSVM: use vmcb_ctrl_area_cached instead of vmcb_control_area in struct svm_nested_state
Date: Wed,  3 Nov 2021 10:05:27 -0400	[thread overview]
Message-ID: <20211103140527.752797-8-eesposit@redhat.com> (raw)
In-Reply-To: <20211103140527.752797-1-eesposit@redhat.com>

This requires changing all vmcb_is_intercept(&svm->nested.ctl, ...)
calls with vmcb12_is_intercept().

In addition, in svm_get_nested_state() user space expects a
vmcb_control_area struct, so we need to copy back all fields
in a temporary structure to provide to the user space.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 arch/x86/kvm/svm/nested.c | 48 +++++++++++++++++++++++++--------------
 arch/x86/kvm/svm/svm.c    |  4 ++--
 arch/x86/kvm/svm/svm.h    |  8 +++----
 3 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index cd15d5373c05..6281d1877211 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -58,8 +58,9 @@ static void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_excep
        struct vcpu_svm *svm = to_svm(vcpu);
        WARN_ON(!is_guest_mode(vcpu));
 
-       if (vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) &&
-	   !svm->nested.nested_run_pending) {
+	if (vmcb12_is_intercept(&svm->nested.ctl,
+				INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) &&
+	    !svm->nested.nested_run_pending) {
                svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + PF_VECTOR;
                svm->vmcb->control.exit_code_hi = 0;
                svm->vmcb->control.exit_info_1 = fault->error_code;
@@ -121,7 +122,8 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
 
 void recalc_intercepts(struct vcpu_svm *svm)
 {
-	struct vmcb_control_area *c, *h, *g;
+	struct vmcb_control_area *c, *h;
+	struct vmcb_ctrl_area_cached *g;
 	unsigned int i;
 
 	vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
@@ -172,7 +174,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 	 */
 	int i;
 
-	if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
+	if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
 		return true;
 
 	for (i = 0; i < MSRPM_OFFSETS; i++) {
@@ -220,9 +222,9 @@ static bool nested_svm_check_tlb_ctl(struct kvm_vcpu *vcpu, u8 tlb_ctl)
 }
 
 static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
-				       struct vmcb_control_area *control)
+				       struct vmcb_ctrl_area_cached *control)
 {
-	if (CC(!vmcb_is_intercept(control, INTERCEPT_VMRUN)))
+	if (CC(!vmcb12_is_intercept(control, INTERCEPT_VMRUN)))
 		return false;
 
 	if (CC(control->asid == 0))
@@ -288,7 +290,7 @@ static bool nested_vmcb_check_save(struct kvm_vcpu *vcpu)
 }
 
 static
-void _nested_copy_vmcb_control_to_cache(struct vmcb_control_area *to,
+void _nested_copy_vmcb_control_to_cache(struct vmcb_ctrl_area_cached *to,
 					struct vmcb_control_area *from)
 {
 	unsigned int i;
@@ -998,7 +1000,7 @@ static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
 	u32 offset, msr, value;
 	int write, mask;
 
-	if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
+	if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
 		return NESTED_EXIT_HOST;
 
 	msr    = svm->vcpu.arch.regs[VCPU_REGS_RCX];
@@ -1025,7 +1027,7 @@ static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
 	u8 start_bit;
 	u64 gpa;
 
-	if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_IOIO_PROT)))
+	if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_IOIO_PROT)))
 		return NESTED_EXIT_HOST;
 
 	port = svm->vmcb->control.exit_info_1 >> 16;
@@ -1056,12 +1058,12 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
 		vmexit = nested_svm_intercept_ioio(svm);
 		break;
 	case SVM_EXIT_READ_CR0 ... SVM_EXIT_WRITE_CR8: {
-		if (vmcb_is_intercept(&svm->nested.ctl, exit_code))
+		if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
 			vmexit = NESTED_EXIT_DONE;
 		break;
 	}
 	case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: {
-		if (vmcb_is_intercept(&svm->nested.ctl, exit_code))
+		if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
 			vmexit = NESTED_EXIT_DONE;
 		break;
 	}
@@ -1079,7 +1081,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
 		break;
 	}
 	default: {
-		if (vmcb_is_intercept(&svm->nested.ctl, exit_code))
+		if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
 			vmexit = NESTED_EXIT_DONE;
 	}
 	}
@@ -1157,7 +1159,7 @@ static void nested_svm_inject_exception_vmexit(struct vcpu_svm *svm)
 
 static inline bool nested_exit_on_init(struct vcpu_svm *svm)
 {
-	return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_INIT);
+	return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_INIT);
 }
 
 static int svm_check_nested_events(struct kvm_vcpu *vcpu)
@@ -1300,6 +1302,8 @@ static int svm_get_nested_state(struct kvm_vcpu *vcpu,
 				u32 user_data_size)
 {
 	struct vcpu_svm *svm;
+	struct vmcb_control_area *ctl;
+	unsigned long r;
 	struct kvm_nested_state kvm_state = {
 		.flags = 0,
 		.format = KVM_STATE_NESTED_FORMAT_SVM,
@@ -1341,9 +1345,18 @@ static int svm_get_nested_state(struct kvm_vcpu *vcpu,
 	 */
 	if (clear_user(user_vmcb, KVM_STATE_NESTED_SVM_VMCB_SIZE))
 		return -EFAULT;
-	if (copy_to_user(&user_vmcb->control, &svm->nested.ctl,
-			 sizeof(user_vmcb->control)))
+
+	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
+	if (!ctl)
+		return -ENOMEM;
+
+	nested_copy_vmcb_cache_to_control(ctl, &svm->nested.ctl);
+	r = copy_to_user(&user_vmcb->control, ctl,
+			 sizeof(user_vmcb->control));
+	kfree(ctl);
+	if (r)
 		return -EFAULT;
+
 	if (copy_to_user(&user_vmcb->save, &svm->vmcb01.ptr->save,
 			 sizeof(user_vmcb->save)))
 		return -EFAULT;
@@ -1361,6 +1374,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 	struct vmcb_control_area *ctl;
 	struct vmcb_save_area *save;
 	struct vmcb_save_area_cached save_cached;
+	struct vmcb_ctrl_area_cached ctl_cached;
 	unsigned long cr0;
 	int ret;
 
@@ -1413,7 +1427,8 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 		goto out_free;
 
 	ret = -EINVAL;
-	if (!nested_vmcb_check_controls(vcpu, ctl))
+	_nested_copy_vmcb_control_to_cache(&ctl_cached, ctl);
+	if (!nested_vmcb_check_controls(vcpu, &ctl_cached))
 		goto out_free;
 
 	/*
@@ -1470,7 +1485,6 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 	svm->nested.vmcb12_gpa = kvm_state->hdr.svm.vmcb_pa;
 
 	svm_copy_vmrun_state(&svm->vmcb01.ptr->save, save);
-	nested_copy_vmcb_control_to_cache(svm, ctl);
 
 	svm_switch_vmcb(svm, &svm->nested.vmcb02);
 	nested_vmcb02_prepare_control(svm);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 74d6db9017ea..134205678462 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2506,7 +2506,7 @@ static bool check_selective_cr0_intercepted(struct kvm_vcpu *vcpu,
 	bool ret = false;
 
 	if (!is_guest_mode(vcpu) ||
-	    (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_SELECTIVE_CR0))))
+	    (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SELECTIVE_CR0))))
 		return false;
 
 	cr0 &= ~SVM_CR0_SELECTIVE_MASK;
@@ -4218,7 +4218,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
 		    info->intercept == x86_intercept_clts)
 			break;
 
-		if (!(vmcb_is_intercept(&svm->nested.ctl,
+		if (!(vmcb12_is_intercept(&svm->nested.ctl,
 					INTERCEPT_SELECTIVE_CR0)))
 			break;
 
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index e29423d4337c..a896a52417ee 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -156,7 +156,7 @@ struct svm_nested_state {
 	bool nested_run_pending;
 
 	/* cache for control fields of the guest */
-	struct vmcb_control_area ctl;
+	struct vmcb_ctrl_area_cached ctl;
 	struct vmcb_save_area_cached save;
 
 	bool initialized;
@@ -494,17 +494,17 @@ static inline bool nested_svm_virtualize_tpr(struct kvm_vcpu *vcpu)
 
 static inline bool nested_exit_on_smi(struct vcpu_svm *svm)
 {
-	return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_SMI);
+	return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SMI);
 }
 
 static inline bool nested_exit_on_intr(struct vcpu_svm *svm)
 {
-	return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_INTR);
+	return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_INTR);
 }
 
 static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
 {
-	return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_NMI);
+	return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_NMI);
 }
 
 int enter_svm_guest_mode(struct kvm_vcpu *vcpu,
-- 
2.27.0


  parent reply	other threads:[~2021-11-03 14:06 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-03 14:05 [PATCH v5 0/7] KVM: nSVM: avoid TOC/TOU race when checking vmcb12 Emanuele Giuseppe Esposito
2021-11-03 14:05 ` [PATCH v5 1/7] KVM: nSVM: move nested_vmcb_check_cr3_cr4 logic in nested_vmcb_valid_sregs Emanuele Giuseppe Esposito
2021-11-03 14:05 ` [PATCH v5 2/7] nSVM: introduce smv->nested.save to cache save area fields Emanuele Giuseppe Esposito
2021-11-03 17:02   ` Maxim Levitsky
2021-11-11 13:52   ` Paolo Bonzini
2021-11-12  7:43     ` Maxim Levitsky
2021-11-03 14:05 ` [PATCH v5 3/7] nSVM: rename nested_load_control_from_vmcb12 in nested_copy_vmcb_control_to_cache Emanuele Giuseppe Esposito
2021-11-03 17:03   ` Maxim Levitsky
2021-11-03 14:05 ` [PATCH v5 4/7] nSVM: use vmcb_save_area_cached in nested_vmcb_valid_sregs() Emanuele Giuseppe Esposito
2021-11-03 17:03   ` Maxim Levitsky
2021-11-03 14:05 ` [PATCH v5 5/7] nSVM: use svm->nested.save to load vmcb12 registers and avoid TOC/TOU races Emanuele Giuseppe Esposito
2021-11-03 14:05 ` [PATCH v5 6/7] nSVM: introduce struct vmcb_ctrl_area_cached Emanuele Giuseppe Esposito
2021-11-03 14:05 ` Emanuele Giuseppe Esposito [this message]
2021-11-03 17:05   ` [PATCH v5 7/7] nSVM: use vmcb_ctrl_area_cached instead of vmcb_control_area in struct svm_nested_state Maxim Levitsky
2021-11-11 13:55 ` [PATCH v5 0/7] KVM: nSVM: avoid TOC/TOU race when checking vmcb12 Paolo Bonzini

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