From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 09/11] KVM: nVMX: Allow the caller to provide instruction length on nested VM-Exit
Date: Fri, 31 Jan 2025 17:55:16 -0800 [thread overview]
Message-ID: <20250201015518.689704-10-seanjc@google.com> (raw)
In-Reply-To: <20250201015518.689704-1-seanjc@google.com>
Rework the nested VM-Exit helper to take the instruction length as a
parameter, and convert nested_vmx_vmexit() into a "default" wrapper that
grabs the length from vmcs02 as appropriate. This will allow KVM to set
the correct instruction length when synthesizing a nested VM-Exit when
emulating an instruction that L1 wants to intercept.
No functional change intended, as the path to prepare_vmcs12()'s reading
of vmcs02.VM_EXIT_INSTRUCTION_LEN is gated on the same set of conditions
as the VMREAD in the new nested_vmx_vmexit().
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/nested.c | 12 +++++++-----
arch/x86/kvm/vmx/nested.h | 22 ++++++++++++++++++++--
2 files changed, 27 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index fb4fd96ce0f8..791e00d467df 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4618,7 +4618,7 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
*/
static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
u32 vm_exit_reason, u32 exit_intr_info,
- unsigned long exit_qualification)
+ unsigned long exit_qualification, u32 exit_insn_len)
{
/* update exit information fields: */
vmcs12->vm_exit_reason = vm_exit_reason;
@@ -4646,7 +4646,7 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
vm_exit_reason, exit_intr_info);
vmcs12->vm_exit_intr_info = exit_intr_info;
- vmcs12->vm_exit_instruction_len = vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+ vmcs12->vm_exit_instruction_len = exit_insn_len;
vmcs12->vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
/*
@@ -4930,8 +4930,9 @@ static void nested_vmx_restore_host_state(struct kvm_vcpu *vcpu)
* and modify vmcs12 to make it see what it would expect to see there if
* L2 was its real guest. Must only be called when in L2 (is_guest_mode())
*/
-void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
- u32 exit_intr_info, unsigned long exit_qualification)
+void __nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
+ u32 exit_intr_info, unsigned long exit_qualification,
+ u32 exit_insn_len)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
@@ -4981,7 +4982,8 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
if (vm_exit_reason != -1)
prepare_vmcs12(vcpu, vmcs12, vm_exit_reason,
- exit_intr_info, exit_qualification);
+ exit_intr_info, exit_qualification,
+ exit_insn_len);
/*
* Must happen outside of sync_vmcs02_to_vmcs12() as it will
diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 2c296b6abb8c..6eedcfc91070 100644
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -26,8 +26,26 @@ void nested_vmx_free_vcpu(struct kvm_vcpu *vcpu);
enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
bool from_vmentry);
bool nested_vmx_reflect_vmexit(struct kvm_vcpu *vcpu);
-void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
- u32 exit_intr_info, unsigned long exit_qualification);
+void __nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
+ u32 exit_intr_info, unsigned long exit_qualification,
+ u32 exit_insn_len);
+
+static inline void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
+ u32 exit_intr_info,
+ unsigned long exit_qualification)
+{
+ u32 exit_insn_len;
+
+ if (to_vmx(vcpu)->fail || vm_exit_reason == -1 ||
+ (vm_exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY))
+ exit_insn_len = 0;
+ else
+ exit_insn_len = vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+
+ __nested_vmx_vmexit(vcpu, vm_exit_reason, exit_intr_info,
+ exit_qualification, exit_insn_len);
+}
+
void nested_sync_vmcs12_to_shadow(struct kvm_vcpu *vcpu);
int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
int vmx_get_vmx_msr(struct nested_vmx_msrs *msrs, u32 msr_index, u64 *pdata);
--
2.48.1.362.g079036d154-goog
next prev parent reply other threads:[~2025-02-01 1:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-01 1:55 [PATCH v2 00/11] KVM: x86: Fix emulation of (some) L2 instructions Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 01/11] KVM: nVMX: Check PAUSE_EXITING, not BUS_LOCK_DETECTION, on PAUSE emulation Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 02/11] KVM: nSVM: Pass next RIP, not current RIP, for nested VM-Exit on emulation Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 03/11] KVM: nVMX: Allow emulating RDPID on behalf of L2 Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 04/11] KVM: nVMX: Emulate HLT in L2 if it's not intercepted Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 05/11] KVM: nVMX: Consolidate missing X86EMUL_INTERCEPTED logic in L2 emulation Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 06/11] KVM: x86: Plumb the src/dst operand types through to .check_intercept() Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 07/11] KVM: x86: Plumb the emulator's starting RIP into nested intercept checks Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 08/11] KVM: x86: Add a #define for the architectural max instruction length Sean Christopherson
2025-02-01 1:55 ` Sean Christopherson [this message]
2025-02-01 1:55 ` [PATCH v2 10/11] KVM: nVMX: Synthesize nested VM-Exit for supported emulation intercepts Sean Christopherson
2025-02-01 1:55 ` [PATCH v2 11/11] KVM: selftests: Add a nested (forced) emulation intercept test for x86 Sean Christopherson
2025-02-28 17:06 ` [PATCH v2 00/11] KVM: x86: Fix emulation of (some) L2 instructions Sean Christopherson
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