[v10,20/81] KVM: x86: add kvm_x86_ops.fault_gla()

Commit Message

Adalbert Lazăr Nov. 25, 2020, 9:34 a.m. UTC

From: Mihai Donțu <[e-mail]>

This function is needed for kvmi_update_ad_flags()
and kvm_page_track_emulation_failure().

kvmi_update_ad_flags() uses the existing guest page table walk code to
update the A/D bits and return to guest (when the introspection tool
write-protects the guest page tables).

kvm_page_track_emulation_failure() calls the page tracking code, that
can trigger an event for the introspection tool (which might need the
GVA in addition to the GPA).

Signed-off-by: Mihai Donțu <[e-mail]>
Co-developed-by: Nicușor Cîțu <[e-mail]>
Signed-off-by: Nicușor Cîțu <[e-mail]>
Signed-off-by: Adalbert Lazăr <[e-mail]>
---
 arch/x86/include/asm/kvm_host.h | 2 ++
 arch/x86/include/asm/vmx.h      | 2 ++
 arch/x86/kvm/svm/svm.c          | 9 +++++++++
 arch/x86/kvm/vmx/vmx.c          | 9 +++++++++
 4 files changed, 22 insertions(+)

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 86048037da23..45c72af05fa2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1303,6 +1303,8 @@  struct kvm_x86_ops {
 
 	void (*migrate_timers)(struct kvm_vcpu *vcpu);
 	void (*msr_filter_changed)(struct kvm_vcpu *vcpu);
+
+	u64 (*fault_gla)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_x86_nested_ops {
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 38ca445a8429..5543332292b5 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -544,6 +544,7 @@  enum vm_entry_failure_code {
 #define EPT_VIOLATION_READABLE_BIT	3
 #define EPT_VIOLATION_WRITABLE_BIT	4
 #define EPT_VIOLATION_EXECUTABLE_BIT	5
+#define EPT_VIOLATION_GLA_VALID_BIT	7
 #define EPT_VIOLATION_GVA_TRANSLATED_BIT 8
 #define EPT_VIOLATION_ACC_READ		(1 << EPT_VIOLATION_ACC_READ_BIT)
 #define EPT_VIOLATION_ACC_WRITE		(1 << EPT_VIOLATION_ACC_WRITE_BIT)
@@ -551,6 +552,7 @@  enum vm_entry_failure_code {
 #define EPT_VIOLATION_READABLE		(1 << EPT_VIOLATION_READABLE_BIT)
 #define EPT_VIOLATION_WRITABLE		(1 << EPT_VIOLATION_WRITABLE_BIT)
 #define EPT_VIOLATION_EXECUTABLE	(1 << EPT_VIOLATION_EXECUTABLE_BIT)
+#define EPT_VIOLATION_GLA_VALID		(1 << EPT_VIOLATION_GLA_VALID_BIT)
 #define EPT_VIOLATION_GVA_TRANSLATED	(1 << EPT_VIOLATION_GVA_TRANSLATED_BIT)
 
 /*
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 43a2e4ec6178..c6730ec39c58 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4314,6 +4314,13 @@  static int svm_vm_init(struct kvm *kvm)
 	return 0;
 }
 
+static u64 svm_fault_gla(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 = {
 	.hardware_unsetup = svm_hardware_teardown,
 	.hardware_enable = svm_hardware_enable,
@@ -4442,6 +4449,8 @@  static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.apic_init_signal_blocked = svm_apic_init_signal_blocked,
 
 	.msr_filter_changed = svm_msr_filter_changed,
+
+	.fault_gla = svm_fault_gla,
 };
 
 static struct kvm_x86_init_ops svm_init_ops __initdata = {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d5d4203378d3..41ea1ee9d419 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7641,6 +7641,13 @@  static int vmx_cpu_dirty_log_size(void)
 	return enable_pml ? PML_ENTITY_NUM : 0;
 }
 
+static u64 vmx_fault_gla(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->arch.exit_qualification & EPT_VIOLATION_GLA_VALID)
+		return vmcs_readl(GUEST_LINEAR_ADDRESS);
+	return ~0ull;
+}
+
 static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.hardware_unsetup = hardware_unsetup,
 
@@ -7779,6 +7786,8 @@  static struct kvm_x86_ops vmx_x86_ops __initdata = {
 
 	.msr_filter_changed = vmx_msr_filter_changed,
 	.cpu_dirty_log_size = vmx_cpu_dirty_log_size,
+
+	.fault_gla = vmx_fault_gla,
 };
 
 static __init int hardware_setup(void)