[PATCH v2 04/24] KVM: VMX: Split out guts of EPT violation to common/exposed function

Yan Zhao
2024-11-12T07:38:01Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

The difference of TDX EPT violation is how to retrieve information, GPA,
and exit qualification. To share the code to handle EPT violation, split
out the guts of EPT violation handler so that VMX/TDX exit handler can call
it after retrieving GPA and exit qualification.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
---
arch/x86/kvm/vmx/common.h | 34 ++++++++++++++++++++++++++++++++++
arch/x86/kvm/vmx/vmx.c | 25 +++----------------------
2 files changed, 37 insertions(+), 22 deletions(-)
create mode 100644 arch/x86/kvm/vmx/common.h

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
new file mode 100644
index 000000000000..78ae39b6cdcd
--- /dev/null
+++ b/arch/x86/kvm/vmx/common.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __KVM_X86_VMX_COMMON_H
+#define __KVM_X86_VMX_COMMON_H
+
+#include <linux/kvm_host.h>
+
+#include "mmu.h"
+
+static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
+ unsigned long exit_qualification)
+{
+ u64 error_code;
+
+ /* Is it a read fault? */
+ error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
+ ? PFERR_USER_MASK : 0;
+ /* Is it a write fault? */
+ error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
+ ? PFERR_WRITE_MASK : 0;
+ /* Is it a fetch fault? */
+ error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
+ ? PFERR_FETCH_MASK : 0;
+ /* ept page table entry is present? */
+ error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
+ ? PFERR_PRESENT_MASK : 0;
+
+ if (error_code & EPT_VIOLATION_GVA_IS_VALID)
+ error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
+ PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
+
+ return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
+}
+
+#endif /* __KVM_X86_VMX_COMMON_H */
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 976fe6579f62..f7ae2359cea2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -53,6 +53,7 @@
#include <trace/events/ipi.h>

#include "capabilities.h"
+#include "common.h"
#include "cpuid.h"
#include "hyperv.h"
#include "kvm_onhyperv.h"
@@ -5774,11 +5775,8 @@ static int handle_task_switch(struct kvm_vcpu *vcpu)

static int handle_ept_violation(struct kvm_vcpu *vcpu)
{
- unsigned long exit_qualification;
+ unsigned long exit_qualification = vmx_get_exit_qual(vcpu);
gpa_t gpa;
- u64 error_code;
-
- exit_qualification = vmx_get_exit_qual(vcpu);

/*
* EPT violation happened while executing iret from NMI,
@@ -5794,23 +5792,6 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
trace_kvm_page_fault(vcpu, gpa, exit_qualification);

- /* Is it a read fault? */
- error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
- ? PFERR_USER_MASK : 0;
- /* Is it a write fault? */
- error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
- ? PFERR_WRITE_MASK : 0;
- /* Is it a fetch fault? */
- error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
- ? PFERR_FETCH_MASK : 0;
- /* ept page table entry is present? */
- error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
- ? PFERR_PRESENT_MASK : 0;
-
- if (error_code & EPT_VIOLATION_GVA_IS_VALID)
- error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
- PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
-
/*
* Check that the GPA doesn't exceed physical memory limits, as that is
* a guest page fault. We have to emulate the instruction here, because
@@ -5822,7 +5803,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
if (unlikely(allow_smaller_maxphyaddr && !kvm_vcpu_is_legal_gpa(vcpu, gpa)))
return kvm_emulate_instruction(vcpu, 0);

- return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
+ return __vmx_handle_ept_violation(vcpu, gpa, exit_qualification);
}

static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
--
2.43.2