From 897861479c0640ed93ec82db78f8d839df32c4ac Mon Sep 17 00:00:00 2001 From: Mohammed Gamal Date: Fri, 10 Jul 2020 17:48:03 +0200 Subject: [PATCH] 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 Signed-off-by: Paolo Bonzini Message-Id: <20200710154811.418214-2-mgamal@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.h | 6 ++++++ arch/x86/kvm/x86.c | 21 +++++++++++++++++++++ arch/x86/kvm/x86.h | 1 + 3 files changed, 28 insertions(+) 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 #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);