[RFC PATCH v2 06/19] KVM: x86: Add kvm_x86_ops.fault_gva()

From: Mickaël Salaün
Date: Sun Nov 12 2023 - 21:24:49 EST


This function is needed for kvm_mmu_page_fault() to create synthetic
page faults.

Code originally written by Mihai Donțu and Nicușor Cîțu:
https://lore.kernel.org/r/20211006173113.26445-18-alazar@xxxxxxxxxxxxxxx
Renamed fault_gla() to fault_gva() and use the new
EPT_VIOLATION_GVA_IS_VALID.

Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Madhavan T. Venkataraman <madvenka@xxxxxxxxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Cc: Wanpeng Li <wanpengli@xxxxxxxxxxx>
Co-developed-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Co-developed-by: Nicușor Cîțu <nicu.citu@xxxxxxxxxx>
Signed-off-by: Nicușor Cîțu <nicu.citu@xxxxxxxxxx>
Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/svm/svm.c | 9 +++++++++
arch/x86/kvm/vmx/vmx.c | 10 ++++++++++
4 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index e3054e3e46d5..ba3db679db2b 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -134,6 +134,7 @@ KVM_X86_OP(msr_filter_changed)
KVM_X86_OP(complete_emulated_msr)
KVM_X86_OP(vcpu_deliver_sipi_vector)
KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons);
+KVM_X86_OP(fault_gva)

#undef KVM_X86_OP
#undef KVM_X86_OP_OPTIONAL
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index dff10051e9b6..0415dacd4b28 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1750,6 +1750,8 @@ struct kvm_x86_ops {
* Returns vCPU specific APICv inhibit reasons
*/
unsigned long (*vcpu_get_apicv_inhibit_reasons)(struct kvm_vcpu *vcpu);
+
+ u64 (*fault_gva)(struct kvm_vcpu *vcpu);
};

struct kvm_x86_nested_ops {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index beea99c8e8e0..d32517a2cf9c 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4906,6 +4906,13 @@ static int svm_vm_init(struct kvm *kvm)
return 0;
}

+static u64 svm_fault_gva(struct kvm_vcpu *vcpu)
+{
+ const struct vcpu_svm *svm = to_svm(vcpu);
+
+ return svm->vcpu.arch.cr2 ? svm->vcpu.arch.cr2 : ~0ull;
+}
+
static struct kvm_x86_ops svm_x86_ops __initdata = {
.name = KBUILD_MODNAME,

@@ -5037,6 +5044,8 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {

.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
.vcpu_get_apicv_inhibit_reasons = avic_vcpu_get_apicv_inhibit_reasons,
+
+ .fault_gva = svm_fault_gva,
};

/*
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 1b1581f578b0..a8158bc1dda9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -8233,6 +8233,14 @@ static void vmx_vm_destroy(struct kvm *kvm)
free_pages((unsigned long)kvm_vmx->pid_table, vmx_get_pid_table_order(kvm));
}

+static u64 vmx_fault_gva(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.exit_qualification & EPT_VIOLATION_GVA_IS_VALID)
+ return vmcs_readl(GUEST_LINEAR_ADDRESS);
+
+ return ~0ull;
+}
+
static struct kvm_x86_ops vmx_x86_ops __initdata = {
.name = KBUILD_MODNAME,

@@ -8373,6 +8381,8 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.complete_emulated_msr = kvm_complete_insn_gp,

.vcpu_deliver_sipi_vector = kvm_vcpu_deliver_sipi_vector,
+
+ .fault_gva = vmx_fault_gva,
};

static unsigned int vmx_handle_intel_pt_intr(void)
--
2.42.1