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Message-Id: <20220311070346.45023-7-jiangshanlai@gmail.com>
Date: Fri, 11 Mar 2022 15:03:46 +0800
From: Lai Jiangshan <jiangshanlai@...il.com>
To: linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
Paolo Bonzini <pbonzini@...hat.com>,
Sean Christopherson <seanjc@...gle.com>
Cc: Lai Jiangshan <jiangshan.ljs@...group.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Wanpeng Li <wanpengli@...cent.com>,
Jim Mattson <jmattson@...gle.com>,
Joerg Roedel <joro@...tes.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
"H. Peter Anvin" <hpa@...or.com>
Subject: [RFC PATCH V2 6/5] KVM: X86: Propagate the nested page fault info to the guest
From: Lai Jiangshan <jiangshan.ljs@...group.com>
Feed the nested page fault info into ->gva_to_gpa() in
walk_addr_generic(), so that the nested walk_addr_generic() can
propagate the nested page fault info into x86_exception.
Propagate the nested page fault info into EXIT_INFO_1 for SVM.
Morph the nested page fault info and other page fault error code into
EXIT_QUOLIFICATION for VMX.
It is a patch that makes use of the patch1.
It is untested, just served as a request for somebody to fix a known
problem, and will not be included in next version of this patchset
if the patchset needs to be updated.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@...group.com>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/kvm_emulate.h | 3 ++-
arch/x86/kvm/mmu/paging_tmpl.h | 8 ++++++--
arch/x86/kvm/svm/nested.c | 10 ++--------
arch/x86/kvm/vmx/nested.c | 11 +++++++++++
5 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 565d9eb42429..68efa9d1ef0e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -265,6 +265,8 @@ enum x86_intercept_stage;
PFERR_WRITE_MASK | \
PFERR_PRESENT_MASK)
+#define PFERR_GUEST_MASK (PFERR_GUEST_FINAL_MASK | PFERR_GUEST_PAGE_MASK)
+
/* apic attention bits */
#define KVM_APIC_CHECK_VAPIC 0
/*
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 39eded2426ff..cdc2977ce086 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -24,8 +24,9 @@ struct x86_exception {
bool error_code_valid;
u16 error_code;
bool nested_page_fault;
- u64 address; /* cr2 or nested page fault gpa */
u8 async_page_fault;
+ u64 nested_pfec; /* nested page fault error code */
+ u64 address; /* cr2 or nested page fault gpa */
};
/*
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 8621188b46df..95367f5ca998 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -383,7 +383,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
* by the MOV to CR instruction are treated as reads and do not cause the
* processor to set the dirty flag in any EPT paging-structure entry.
*/
- nested_access = (have_ad ? PFERR_WRITE_MASK : 0) | PFERR_USER_MASK;
+ nested_access = (have_ad ? PFERR_WRITE_MASK : 0) | PFERR_USER_MASK |
+ PFERR_GUEST_PAGE_MASK;
pte_access = ~0;
++walker->level;
@@ -466,7 +467,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
if (PTTYPE == 32 && walker->level > PG_LEVEL_4K && is_cpuid_PSE36())
gfn += pse36_gfn_delta(pte);
- real_gpa = kvm_translate_gpa(vcpu, mmu, gfn_to_gpa(gfn), access, &walker->fault);
+ real_gpa = kvm_translate_gpa(vcpu, mmu, gfn_to_gpa(gfn),
+ access | PFERR_GUEST_FINAL_MASK, &walker->fault);
if (real_gpa == UNMAPPED_GVA)
return 0;
@@ -534,6 +536,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
walker->fault.address = addr;
walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu;
walker->fault.async_page_fault = false;
+ if (walker->fault.nested_page_fault)
+ walker->fault.nested_pfec = errcode | (access & PFERR_GUEST_MASK);
trace_kvm_mmu_walker_error(walker->fault.error_code);
return 0;
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 96bab464967f..0abcbd3de892 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -38,18 +38,12 @@ static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
struct vcpu_svm *svm = to_svm(vcpu);
if (svm->vmcb->control.exit_code != SVM_EXIT_NPF) {
- /*
- * TODO: track the cause of the nested page fault, and
- * correctly fill in the high bits of exit_info_1.
- */
svm->vmcb->control.exit_code = SVM_EXIT_NPF;
svm->vmcb->control.exit_code_hi = 0;
- svm->vmcb->control.exit_info_1 = (1ULL << 32);
- svm->vmcb->control.exit_info_2 = fault->address;
}
- svm->vmcb->control.exit_info_1 &= ~0xffffffffULL;
- svm->vmcb->control.exit_info_1 |= fault->error_code;
+ svm->vmcb->control.exit_info_1 = fault->nested_pfec;
+ svm->vmcb->control.exit_info_2 = fault->address;
nested_svm_vmexit(svm);
}
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1dfe23963a9e..fd5dd5acf63b 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -372,6 +372,17 @@ static void nested_ept_inject_page_fault(struct kvm_vcpu *vcpu,
u32 vm_exit_reason;
unsigned long exit_qualification = vcpu->arch.exit_qualification;
+ exit_qualification &= ~(EPT_VIOLATION_ACC_READ | EPT_VIOLATION_ACC_WRITE |
+ EPT_VIOLATION_ACC_INSTR | EPT_VIOLATION_GVA_TRANSLATED);
+ exit_qualification |= fault->nested_pfec & PFERR_USER_MASK ?
+ EPT_VIOLATION_ACC_READ : 0;
+ exit_qualification |= fault->nested_pfec & PFERR_WRITE_MASK ?
+ EPT_VIOLATION_ACC_WRITE : 0;
+ exit_qualification |= fault->nested_pfec & PFERR_FETCH_MASK ?
+ EPT_VIOLATION_ACC_INSTR : 0;
+ exit_qualification |= fault->nested_pfec & PFERR_GUEST_FINAL_MASK ?
+ EPT_VIOLATION_GVA_TRANSLATED : 0;
+
if (vmx->nested.pml_full) {
vm_exit_reason = EXIT_REASON_PML_FULL;
vmx->nested.pml_full = false;
--
2.19.1.6.gb485710b
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