Revert "KVM: Support vCPU-based gfn->hva cache"

commit 4e335d9e7ddbcf83d03e7fbe65797ebed2272c18 upstream.

This reverts commit bbd6411513aa8ef3ea02abab61318daf87c1af1e.

I've been sitting on this revert for too long and it unfortunately
missed 4.11.  It's also the reason why I haven't merged ring-based
dirty tracking for 4.12.

Using kvm_vcpu_memslots in kvm_gfn_to_hva_cache_init and
kvm_vcpu_write_guest_offset_cached means that the MSR value can
now be used to access SMRAM, simply by making it point to an SMRAM
physical address.  This is problematic because it lets the guest
OS overwrite memory that it shouldn't be able to touch.

Fixes: bbd6411513aa8ef3ea02abab61318daf87c1af1e
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index bad6a25067bc0c74bd2b904d8bca21b141bbc7f4..9fa5b816496199d00c437707a45074f14a859150 100644 (file)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -529,14 +529,16 @@ int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
 
 static int pv_eoi_put_user(struct kvm_vcpu *vcpu, u8 val)
 {
-       return kvm_vcpu_write_guest_cached(vcpu, &vcpu->arch.pv_eoi.data, &val,
-                                          sizeof(val));
+
+       return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data, &val,
+                                     sizeof(val));
 }
 
 static int pv_eoi_get_user(struct kvm_vcpu *vcpu, u8 *val)
 {
-       return kvm_vcpu_read_guest_cached(vcpu, &vcpu->arch.pv_eoi.data, val,
-                                         sizeof(*val));
+
+       return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data, val,
+                                     sizeof(*val));
 }
 
 static inline bool pv_eoi_enabled(struct kvm_vcpu *vcpu)
@@ -2285,8 +2287,8 @@ void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
        if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
                return;
 
-       if (kvm_vcpu_read_guest_cached(vcpu, &vcpu->arch.apic->vapic_cache, &data,
-                                      sizeof(u32)))
+       if (kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data,
+                                 sizeof(u32)))
                return;
 
        apic_set_tpr(vcpu->arch.apic, data & 0xff);
@@ -2338,14 +2340,14 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
                max_isr = 0;
        data = (tpr & 0xff) | ((max_isr & 0xf0) << 8) | (max_irr << 24);
 
-       kvm_vcpu_write_guest_cached(vcpu, &vcpu->arch.apic->vapic_cache, &data,
-                                   sizeof(u32));
+       kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data,
+                               sizeof(u32));
 }
 
 int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
 {
        if (vapic_addr) {
-               if (kvm_vcpu_gfn_to_hva_cache_init(vcpu,
+               if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
                                        &vcpu->arch.apic->vapic_cache,
                                        vapic_addr, sizeof(u32)))
                        return -EINVAL;
@@ -2439,7 +2441,7 @@ int kvm_lapic_enable_pv_eoi(struct kvm_vcpu *vcpu, u64 data)
        vcpu->arch.pv_eoi.msr_val = data;
        if (!pv_eoi_enabled(vcpu))
                return 0;
-       return kvm_vcpu_gfn_to_hva_cache_init(vcpu, &vcpu->arch.pv_eoi.data,
+       return kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.pv_eoi.data,
                                         addr, sizeof(u8));
 }
 

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c9adc6a64b9ff2707711d9dffab44c92f8e2db97..421a069b5429e9984f1c252424d1b1fb5072c33f 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1813,7 +1813,7 @@ static void kvm_setup_pvclock_page(struct kvm_vcpu *v)
        struct kvm_vcpu_arch *vcpu = &v->arch;
        struct pvclock_vcpu_time_info guest_hv_clock;
 
-       if (unlikely(kvm_vcpu_read_guest_cached(v, &vcpu->pv_time,
+       if (unlikely(kvm_read_guest_cached(v->kvm, &vcpu->pv_time,
                &guest_hv_clock, sizeof(guest_hv_clock))))
                return;
 
@@ -1834,9 +1834,9 @@ static void kvm_setup_pvclock_page(struct kvm_vcpu *v)
        BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);
 
        vcpu->hv_clock.version = guest_hv_clock.version + 1;
-       kvm_vcpu_write_guest_cached(v, &vcpu->pv_time,
-                                   &vcpu->hv_clock,
-                                   sizeof(vcpu->hv_clock.version));
+       kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
+                               &vcpu->hv_clock,
+                               sizeof(vcpu->hv_clock.version));
 
        smp_wmb();
 
@@ -1850,16 +1850,16 @@ static void kvm_setup_pvclock_page(struct kvm_vcpu *v)
 
        trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock);
 
-       kvm_vcpu_write_guest_cached(v, &vcpu->pv_time,
-                                   &vcpu->hv_clock,
-                                   sizeof(vcpu->hv_clock));
+       kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
+                               &vcpu->hv_clock,
+                               sizeof(vcpu->hv_clock));
 
        smp_wmb();
 
        vcpu->hv_clock.version++;
-       kvm_vcpu_write_guest_cached(v, &vcpu->pv_time,
-                                   &vcpu->hv_clock,
-                                   sizeof(vcpu->hv_clock.version));
+       kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
+                               &vcpu->hv_clock,
+                               sizeof(vcpu->hv_clock.version));
 }
 
 static int kvm_guest_time_update(struct kvm_vcpu *v)
@@ -2092,7 +2092,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
                return 0;
        }
 
-       if (kvm_vcpu_gfn_to_hva_cache_init(vcpu, &vcpu->arch.apf.data, gpa,
+       if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa,
                                        sizeof(u32)))
                return 1;
 
@@ -2111,7 +2111,7 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
        if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
                return;
 
-       if (unlikely(kvm_vcpu_read_guest_cached(vcpu, &vcpu->arch.st.stime,
+       if (unlikely(kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
                &vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
                return;
 
@@ -2122,7 +2122,7 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
 
        vcpu->arch.st.steal.version += 1;
 
-       kvm_vcpu_write_guest_cached(vcpu, &vcpu->arch.st.stime,
+       kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
                &vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
 
        smp_wmb();
@@ -2131,14 +2131,14 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
                vcpu->arch.st.last_steal;
        vcpu->arch.st.last_steal = current->sched_info.run_delay;
 
-       kvm_vcpu_write_guest_cached(vcpu, &vcpu->arch.st.stime,
+       kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
                &vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
 
        smp_wmb();
 
        vcpu->arch.st.steal.version += 1;
 
-       kvm_vcpu_write_guest_cached(vcpu, &vcpu->arch.st.stime,
+       kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
                &vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
 }
 
@@ -2243,7 +2243,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                if (!(data & 1))
                        break;
 
-               if (kvm_vcpu_gfn_to_hva_cache_init(vcpu,
+               if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
                     &vcpu->arch.pv_time, data & ~1ULL,
                     sizeof(struct pvclock_vcpu_time_info)))
                        vcpu->arch.pv_time_enabled = false;
@@ -2264,7 +2264,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                if (data & KVM_STEAL_RESERVED_MASK)
                        return 1;
 
-               if (kvm_vcpu_gfn_to_hva_cache_init(vcpu, &vcpu->arch.st.stime,
+               if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.st.stime,
                                                data & KVM_STEAL_VALID_BITS,
                                                sizeof(struct kvm_steal_time)))
                        return 1;
@@ -2878,7 +2878,7 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
 
        vcpu->arch.st.steal.preempted = 1;
 
-       kvm_vcpu_write_guest_offset_cached(vcpu, &vcpu->arch.st.stime,
+       kvm_write_guest_offset_cached(vcpu->kvm, &vcpu->arch.st.stime,
                        &vcpu->arch.st.steal.preempted,
                        offsetof(struct kvm_steal_time, preempted),
                        sizeof(vcpu->arch.st.steal.preempted));
@@ -8548,8 +8548,9 @@ static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
 
 static int apf_put_user(struct kvm_vcpu *vcpu, u32 val)
 {
-       return kvm_vcpu_write_guest_cached(vcpu, &vcpu->arch.apf.data, &val,
-                                          sizeof(val));
+
+       return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &val,
+                                     sizeof(val));
 }
 
 void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d0250744507a284138d0e7e702bb64e1d205e769..333af5a41c78efc9b622bd9fd9989d39ee7f3851 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -641,18 +641,18 @@ int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
                          unsigned long len);
 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len);
-int kvm_vcpu_read_guest_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_cache *ghc,
-                              void *data, unsigned long len);
+int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                          void *data, unsigned long len);
 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
                         int offset, int len);
 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
                    unsigned long len);
-int kvm_vcpu_write_guest_cached(struct kvm_vcpu *v, struct gfn_to_hva_cache *ghc,
-                               void *data, unsigned long len);
-int kvm_vcpu_write_guest_offset_cached(struct kvm_vcpu *v, struct gfn_to_hva_cache *ghc,
-                                      void *data, int offset, unsigned long len);
-int kvm_vcpu_gfn_to_hva_cache_init(struct kvm_vcpu *v, struct gfn_to_hva_cache *ghc,
-                                  gpa_t gpa, unsigned long len);
+int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                          void *data, unsigned long len);
+int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                          void *data, int offset, unsigned long len);
+int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                             gpa_t gpa, unsigned long len);
 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len);
 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len);
 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn);

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 88257b311cb579b5b720330456f99fbec97a58ac..7e80f62f034c16f9192c2ab73b3d2e8804675e2c 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1973,18 +1973,18 @@ static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
        return 0;
 }
 
-int kvm_vcpu_gfn_to_hva_cache_init(struct kvm_vcpu *vcpu, struct gfn_to_hva_cache *ghc,
+int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
                              gpa_t gpa, unsigned long len)
 {
-       struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu);
+       struct kvm_memslots *slots = kvm_memslots(kvm);
        return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len);
 }
-EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva_cache_init);
+EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
 
-int kvm_vcpu_write_guest_offset_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_cache *ghc,
-                                      void *data, int offset, unsigned long len)
+int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                          void *data, int offset, unsigned long len)
 {
-       struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu);
+       struct kvm_memslots *slots = kvm_memslots(kvm);
        int r;
        gpa_t gpa = ghc->gpa + offset;
 
@@ -1994,7 +1994,7 @@ int kvm_vcpu_write_guest_offset_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_
                __kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len);
 
        if (unlikely(!ghc->memslot))
-               return kvm_vcpu_write_guest(vcpu, gpa, data, len);
+               return kvm_write_guest(kvm, gpa, data, len);
 
        if (kvm_is_error_hva(ghc->hva))
                return -EFAULT;
@@ -2006,19 +2006,19 @@ int kvm_vcpu_write_guest_offset_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_offset_cached);
+EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached);
 
-int kvm_vcpu_write_guest_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_cache *ghc,
-                              void *data, unsigned long len)
+int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                          void *data, unsigned long len)
 {
-       return kvm_vcpu_write_guest_offset_cached(vcpu, ghc, data, 0, len);
+       return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len);
 }
-EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_cached);
+EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
 
-int kvm_vcpu_read_guest_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_cache *ghc,
-                              void *data, unsigned long len)
+int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                          void *data, unsigned long len)
 {
-       struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu);
+       struct kvm_memslots *slots = kvm_memslots(kvm);
        int r;
 
        BUG_ON(len > ghc->len);
@@ -2027,7 +2027,7 @@ int kvm_vcpu_read_guest_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_cache *g
                __kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len);
 
        if (unlikely(!ghc->memslot))
-               return kvm_vcpu_read_guest(vcpu, ghc->gpa, data, len);
+               return kvm_read_guest(kvm, ghc->gpa, data, len);
 
        if (kvm_is_error_hva(ghc->hva))
                return -EFAULT;
@@ -2038,7 +2038,7 @@ int kvm_vcpu_read_guest_cached(struct kvm_vcpu *vcpu, struct gfn_to_hva_cache *g
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_cached);
+EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
 
 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
 {