KVM: x86/mmu: Use 64-bit address to invalidate to fix a subtle bug

FNAME(invlpg)() and kvm_mmu_invalidate_gva() take a gva_t, i.e. unsigned
long, as the type of the address to invalidate.  On 32-bit kernels, the
upper 32 bits of the GPA will get dropped when an L2 GPA address is
invalidated in the shadowed nested TDP MMU.

Convert it to u64 to fix the problem.

Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Link: https://lore.kernel.org/r/20230216154115.710033-2-jiangshanlai@gmail.com
[sean: tweak changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a45de11..2146365 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -441,7 +441,7 @@ struct kvm_mmu {
                            struct x86_exception *exception);
        int (*sync_page)(struct kvm_vcpu *vcpu,
                         struct kvm_mmu_page *sp);
-       void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa);
+       void (*invlpg)(struct kvm_vcpu *vcpu, u64 addr, hpa_t root_hpa);
        struct kvm_mmu_root_info root;
        union kvm_cpu_role cpu_role;
        union kvm_mmu_page_role root_role;
@@ -2044,8 +2044,8 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);
 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
                       void *insn, int insn_len);
 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva);
-void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
-                           gva_t gva, hpa_t root_hpa);
+void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+                            u64 addr, hpa_t root_hpa);
 void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid);
 void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd);
 

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 144c5a0..edad1a4 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5707,25 +5707,25 @@ emulate:
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
 
-void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
-                           gva_t gva, hpa_t root_hpa)
+void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+                            u64 addr, hpa_t root_hpa)
 {
        int i;
 
        /* It's actually a GPA for vcpu->arch.guest_mmu.  */
        if (mmu != &vcpu->arch.guest_mmu) {
                /* INVLPG on a non-canonical address is a NOP according to the SDM.  */
-               if (is_noncanonical_address(gva, vcpu))
+               if (is_noncanonical_address(addr, vcpu))
                        return;
 
-               static_call(kvm_x86_flush_tlb_gva)(vcpu, gva);
+               static_call(kvm_x86_flush_tlb_gva)(vcpu, addr);
        }
 
        if (!mmu->invlpg)
                return;
 
        if (root_hpa == INVALID_PAGE) {
-               mmu->invlpg(vcpu, gva, mmu->root.hpa);
+               mmu->invlpg(vcpu, addr, mmu->root.hpa);
 
                /*
                 * INVLPG is required to invalidate any global mappings for the VA,
@@ -5740,15 +5740,15 @@ void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
                 */
                for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++)
                        if (VALID_PAGE(mmu->prev_roots[i].hpa))
-                               mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa);
+                               mmu->invlpg(vcpu, addr, mmu->prev_roots[i].hpa);
        } else {
-               mmu->invlpg(vcpu, gva, root_hpa);
+               mmu->invlpg(vcpu, addr, root_hpa);
        }
 }
 
 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
 {
-       kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE);
+       kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE);
        ++vcpu->stat.invlpg;
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index a056f27..0a9c11c 100644 (file)
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -846,7 +846,8 @@ static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp)
        return gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t);
 }
 
-static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
+/* Note, @addr is a GPA when invlpg() invalidates an L2 GPA translation in shadowed TDP */
+static void FNAME(invlpg)(struct kvm_vcpu *vcpu, u64 addr, hpa_t root_hpa)
 {
        struct kvm_shadow_walk_iterator iterator;
        struct kvm_mmu_page *sp;
@@ -854,7 +855,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
        int level;
        u64 *sptep;
 
-       vcpu_clear_mmio_info(vcpu, gva);
+       vcpu_clear_mmio_info(vcpu, addr);
 
        /*
         * No need to check return value here, rmap_can_add() can
@@ -868,7 +869,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
        }
 
        write_lock(&vcpu->kvm->mmu_lock);
-       for_each_shadow_entry_using_root(vcpu, root_hpa, gva, iterator) {
+       for_each_shadow_entry_using_root(vcpu, root_hpa, addr, iterator) {
                level = iterator.level;
                sptep = iterator.sptep;
 

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 237c483..0b6b587 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -802,8 +802,8 @@ void kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
         */
        if ((fault->error_code & PFERR_PRESENT_MASK) &&
            !(fault->error_code & PFERR_RSVD_MASK))
-               kvm_mmu_invalidate_gva(vcpu, fault_mmu, fault->address,
-                                      fault_mmu->root.hpa);
+               kvm_mmu_invalidate_addr(vcpu, fault_mmu, fault->address,
+                                       fault_mmu->root.hpa);
 
        fault_mmu->inject_page_fault(vcpu, fault);
 }