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authorMohammed Gamal <mgamal@redhat.com>2020-07-10 17:48:03 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2020-07-10 13:07:28 -0400
commit897861479c0640ed93ec82db78f8d839df32c4ac (patch)
treeaa634837e4caa13734f5e25800b727e2955e3787
parentfe9304d31831c9ee3943f9a6f72b7cea16d4bc11 (diff)
downloadlinux-897861479c0640ed93ec82db78f8d839df32c4ac.tar.bz2
KVM: x86: Add helper functions for illegal GPA checking and page fault injection
This patch adds two helper functions that will be used to support virtualizing MAXPHYADDR in both kvm-intel.ko and kvm.ko. kvm_fixup_and_inject_pf_error() injects a page fault for a user-specified GVA, while kvm_mmu_is_illegal_gpa() checks whether a GPA exceeds vCPU address limits. Signed-off-by: Mohammed Gamal <mgamal@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200710154811.418214-2-mgamal@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu.h6
-rw-r--r--arch/x86/kvm/x86.c21
-rw-r--r--arch/x86/kvm/x86.h1
3 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 75125ae57e50..9f6554613bab 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -4,6 +4,7 @@
#include <linux/kvm_host.h>
#include "kvm_cache_regs.h"
+#include "cpuid.h"
#define PT64_PT_BITS 9
#define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
@@ -150,6 +151,11 @@ static inline bool is_write_protection(struct kvm_vcpu *vcpu)
return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
}
+static inline bool kvm_mmu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
+{
+ return (gpa >= BIT_ULL(cpuid_maxphyaddr(vcpu)));
+}
+
/*
* Check if a given access (described through the I/D, W/R and U/S bits of a
* page fault error code pfec) causes a permission fault with the given PTE
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 69a2e9c981e9..0867a626b226 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10738,6 +10738,27 @@ int kvm_spec_ctrl_test_value(u64 value)
}
EXPORT_SYMBOL_GPL(kvm_spec_ctrl_test_value);
+void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_code)
+{
+ struct x86_exception fault;
+
+ if (!(error_code & PFERR_PRESENT_MASK) ||
+ vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, error_code, &fault) != UNMAPPED_GVA) {
+ /*
+ * If vcpu->arch.walk_mmu->gva_to_gpa succeeded, the page
+ * tables probably do not match the TLB. Just proceed
+ * with the error code that the processor gave.
+ */
+ fault.vector = PF_VECTOR;
+ fault.error_code_valid = true;
+ fault.error_code = error_code;
+ fault.nested_page_fault = false;
+ fault.address = gva;
+ }
+ vcpu->arch.walk_mmu->inject_page_fault(vcpu, &fault);
+}
+EXPORT_SYMBOL_GPL(kvm_fixup_and_inject_pf_error);
+
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 3308c3ccc0fd..995ab696dcf0 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -272,6 +272,7 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata);
bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn,
int page_num);
bool kvm_vector_hashing_enabled(void);
+void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_code);
int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
int emulation_type, void *insn, int insn_len);
fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu);