From ca0bde28f2ed66c2229ecfb7f4bfa0defa3da4b5 Mon Sep 17 00:00:00 2001
From: Jim Mattson <jmattson@google.com>
Date: Wed, 30 Nov 2016 12:03:46 -0800
Subject: [PATCH] kvm: nVMX: Split VMCS checks from nested_vmx_run()
The checks performed on the contents of the vmcs12 are extracted from
nested_vmx_run so that they can be used to validate a vmcs12 that has
been restored from a checkpoint.
Signed-off-by: Jim Mattson <jmattson@google.com>
[Change prepare_vmcs02 and nested_vmx_load_cr3's last argument to u32,
to match check_vmentry_postreqs. Update comments for singlestep
handling. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx.c | 194 ++++++++++++++++++++++++---------------------
1 file changed, 103 insertions(+), 91 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 650f34336fada..71df7411959fe 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10035,7 +10035,7 @@ static bool nested_cr3_valid(struct kvm_vcpu *vcpu, unsigned long val)
* is assigned to entry_failure_code on failure.
*/
static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool nested_ept,
- unsigned long *entry_failure_code)
+ u32 *entry_failure_code)
{
if (cr3 != kvm_read_cr3(vcpu) || (!nested_ept && pdptrs_changed(vcpu))) {
if (!nested_cr3_valid(vcpu, cr3)) {
@@ -10075,7 +10075,7 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne
* is assigned to entry_failure_code on failure.
*/
static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
- bool from_vmentry, unsigned long *entry_failure_code)
+ bool from_vmentry, u32 *entry_failure_code)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 exec_control;
@@ -10411,68 +10411,22 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
return 0;
}
-/*
- * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1
- * for running an L2 nested guest.
- */
-static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
+static int check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
- struct vmcs12 *vmcs12;
struct vcpu_vmx *vmx = to_vmx(vcpu);
- int cpu;
- struct loaded_vmcs *vmcs02;
- bool ia32e;
- u32 msr_entry_idx;
- unsigned long exit_qualification;
-
- if (!nested_vmx_check_permission(vcpu))
- return 1;
-
- if (!nested_vmx_check_vmcs12(vcpu))
- goto out;
-
- vmcs12 = get_vmcs12(vcpu);
-
- if (enable_shadow_vmcs)
- copy_shadow_to_vmcs12(vmx);
-
- /*
- * The nested entry process starts with enforcing various prerequisites
- * on vmcs12 as required by the Intel SDM, and act appropriately when
- * they fail: As the SDM explains, some conditions should cause the
- * instruction to fail, while others will cause the instruction to seem
- * to succeed, but return an EXIT_REASON_INVALID_STATE.
- * To speed up the normal (success) code path, we should avoid checking
- * for misconfigurations which will anyway be caught by the processor
- * when using the merged vmcs02.
- */
- if (vmcs12->launch_state == launch) {
- nested_vmx_failValid(vcpu,
- launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS
- : VMXERR_VMRESUME_NONLAUNCHED_VMCS);
- goto out;
- }
if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE &&
- vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT) {
- nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
- goto out;
- }
+ vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT)
+ return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
- if (nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12)) {
- nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
- goto out;
- }
+ if (nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12))
+ return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
- if (nested_vmx_check_apicv_controls(vcpu, vmcs12)) {
- nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
- goto out;
- }
+ if (nested_vmx_check_apicv_controls(vcpu, vmcs12))
+ return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
- if (nested_vmx_check_msr_switch_controls(vcpu, vmcs12)) {
- nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
- goto out;
- }
+ if (nested_vmx_check_msr_switch_controls(vcpu, vmcs12))
+ return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
if (!vmx_control_verify(vmcs12->cpu_based_vm_exec_control,
vmx->nested.nested_vmx_procbased_ctls_low,
@@ -10489,28 +10443,30 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
!vmx_control_verify(vmcs12->vm_entry_controls,
vmx->nested.nested_vmx_entry_ctls_low,
vmx->nested.nested_vmx_entry_ctls_high))
- {
- nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
- goto out;
- }
+ return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
if (!nested_host_cr0_valid(vcpu, vmcs12->host_cr0) ||
!nested_host_cr4_valid(vcpu, vmcs12->host_cr4) ||
- !nested_cr3_valid(vcpu, vmcs12->host_cr3)) {
- nested_vmx_failValid(vcpu,
- VMXERR_ENTRY_INVALID_HOST_STATE_FIELD);
- goto out;
- }
+ !nested_cr3_valid(vcpu, vmcs12->host_cr3))
+ return VMXERR_ENTRY_INVALID_HOST_STATE_FIELD;
+
+ return 0;
+}
+
+static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
+ u32 *exit_qual)
+{
+ bool ia32e;
+
+ *exit_qual = ENTRY_FAIL_DEFAULT;
if (!nested_guest_cr0_valid(vcpu, vmcs12->guest_cr0) ||
- !nested_guest_cr4_valid(vcpu, vmcs12->guest_cr4)) {
- nested_vmx_entry_failure(vcpu, vmcs12,
- EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT);
+ !nested_guest_cr4_valid(vcpu, vmcs12->guest_cr4))
return 1;
- }
- if (vmcs12->vmcs_link_pointer != -1ull) {
- nested_vmx_entry_failure(vcpu, vmcs12,
- EXIT_REASON_INVALID_STATE, ENTRY_FAIL_VMCS_LINK_PTR);
+
+ if (!nested_cpu_has2(vmcs12, SECONDARY_EXEC_SHADOW_VMCS) &&
+ vmcs12->vmcs_link_pointer != -1ull) {
+ *exit_qual = ENTRY_FAIL_VMCS_LINK_PTR;
return 1;
}
@@ -10523,16 +10479,14 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
* to bit 8 (LME) if bit 31 in the CR0 field (corresponding to
* CR0.PG) is 1.
*/
- if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER) {
+ if (to_vmx(vcpu)->nested.nested_run_pending &&
+ (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)) {
ia32e = (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) != 0;
if (!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer) ||
ia32e != !!(vmcs12->guest_ia32_efer & EFER_LMA) ||
((vmcs12->guest_cr0 & X86_CR0_PG) &&
- ia32e != !!(vmcs12->guest_ia32_efer & EFER_LME))) {
- nested_vmx_entry_failure(vcpu, vmcs12,
- EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT);
+ ia32e != !!(vmcs12->guest_ia32_efer & EFER_LME)))
return 1;
- }
}
/*
@@ -10546,11 +10500,75 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
VM_EXIT_HOST_ADDR_SPACE_SIZE) != 0;
if (!kvm_valid_efer(vcpu, vmcs12->host_ia32_efer) ||
ia32e != !!(vmcs12->host_ia32_efer & EFER_LMA) ||
- ia32e != !!(vmcs12->host_ia32_efer & EFER_LME)) {
- nested_vmx_entry_failure(vcpu, vmcs12,
- EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT);
+ ia32e != !!(vmcs12->host_ia32_efer & EFER_LME))
return 1;
- }
+ }
+
+ return 0;
+}
+
+/*
+ * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1
+ * for running an L2 nested guest.
+ */
+static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
+{
+ struct vmcs12 *vmcs12;
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ int cpu;
+ struct loaded_vmcs *vmcs02;
+ u32 msr_entry_idx;
+ u32 exit_qual;
+ int ret;
+
+ if (!nested_vmx_check_permission(vcpu))
+ return 1;
+
+ if (!nested_vmx_check_vmcs12(vcpu))
+ goto out;
+
+ vmcs12 = get_vmcs12(vcpu);
+
+ if (enable_shadow_vmcs)
+ copy_shadow_to_vmcs12(vmx);
+
+ /*
+ * The nested entry process starts with enforcing various prerequisites
+ * on vmcs12 as required by the Intel SDM, and act appropriately when
+ * they fail: As the SDM explains, some conditions should cause the
+ * instruction to fail, while others will cause the instruction to seem
+ * to succeed, but return an EXIT_REASON_INVALID_STATE.
+ * To speed up the normal (success) code path, we should avoid checking
+ * for misconfigurations which will anyway be caught by the processor
+ * when using the merged vmcs02.
+ */
+ if (vmcs12->launch_state == launch) {
+ nested_vmx_failValid(vcpu,
+ launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS
+ : VMXERR_VMRESUME_NONLAUNCHED_VMCS);
+ goto out;
+ }
+
+ ret = check_vmentry_prereqs(vcpu, vmcs12);
+ if (ret) {
+ nested_vmx_failValid(vcpu, ret);
+ goto out;
+ }
+
+ /*
+ * After this point, the trap flag no longer triggers a singlestep trap
+ * on the vm entry instructions; don't call kvm_skip_emulated_instruction.
+ * This is not 100% correct; for performance reasons, we delegate most
+ * of the checks on host state to the processor. If those fail,
+ * the singlestep trap is missed.
+ */
+ skip_emulated_instruction(vcpu);
+
+ ret = check_vmentry_postreqs(vcpu, vmcs12, &exit_qual);
+ if (ret) {
+ nested_vmx_entry_failure(vcpu, vmcs12,
+ EXIT_REASON_INVALID_STATE, exit_qual);
+ return 1;
}
/*
@@ -10562,12 +10580,6 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
if (!vmcs02)
return -ENOMEM;
- /*
- * After this point, the trap flag no longer triggers a singlestep trap
- * on the vm entry instructions. Don't call
- * kvm_skip_emulated_instruction.
- */
- skip_emulated_instruction(vcpu);
enter_guest_mode(vcpu);
if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
@@ -10582,11 +10594,11 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
vmx_segment_cache_clear(vmx);
- if (prepare_vmcs02(vcpu, vmcs12, true, &exit_qualification)) {
+ if (prepare_vmcs02(vcpu, vmcs12, true, &exit_qual)) {
leave_guest_mode(vcpu);
vmx_load_vmcs01(vcpu);
nested_vmx_entry_failure(vcpu, vmcs12,
- EXIT_REASON_INVALID_STATE, exit_qualification);
+ EXIT_REASON_INVALID_STATE, exit_qual);
return 1;
}
@@ -10937,7 +10949,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
struct kvm_segment seg;
- unsigned long entry_failure_code;
+ u32 entry_failure_code;
if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER)
vcpu->arch.efer = vmcs12->host_ia32_efer;