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Diffstat (limited to 'arch/x86/kvm/xen.c')
-rw-r--r--arch/x86/kvm/xen.c97
1 files changed, 67 insertions, 30 deletions
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index bad57535fad0..74be1fda58e3 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -133,32 +133,57 @@ static void kvm_xen_update_runstate(struct kvm_vcpu *v, int state)
void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
{
struct kvm_vcpu_xen *vx = &v->arch.xen;
+ struct gfn_to_hva_cache *ghc = &vx->runstate_cache;
+ struct kvm_memslots *slots = kvm_memslots(v->kvm);
+ bool atomic = (state == RUNSTATE_runnable);
uint64_t state_entry_time;
- unsigned int offset;
+ int __user *user_state;
+ uint64_t __user *user_times;
kvm_xen_update_runstate(v, state);
if (!vx->runstate_set)
return;
- BUILD_BUG_ON(sizeof(struct compat_vcpu_runstate_info) != 0x2c);
+ if (unlikely(slots->generation != ghc->generation || kvm_is_error_hva(ghc->hva)) &&
+ kvm_gfn_to_hva_cache_init(v->kvm, ghc, ghc->gpa, ghc->len))
+ return;
+
+ /* We made sure it fits in a single page */
+ BUG_ON(!ghc->memslot);
+
+ if (atomic)
+ pagefault_disable();
- offset = offsetof(struct compat_vcpu_runstate_info, state_entry_time);
-#ifdef CONFIG_X86_64
/*
- * The only difference is alignment of uint64_t in 32-bit.
- * So the first field 'state' is accessed directly using
- * offsetof() (where its offset happens to be zero), while the
- * remaining fields which are all uint64_t, start at 'offset'
- * which we tweak here by adding 4.
+ * The only difference between 32-bit and 64-bit versions of the
+ * runstate struct us the alignment of uint64_t in 32-bit, which
+ * means that the 64-bit version has an additional 4 bytes of
+ * padding after the first field 'state'.
+ *
+ * So we use 'int __user *user_state' to point to the state field,
+ * and 'uint64_t __user *user_times' for runstate_entry_time. So
+ * the actual array of time[] in each state starts at user_times[1].
*/
+ BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) != 0);
+ BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state) != 0);
+ user_state = (int __user *)ghc->hva;
+
+ BUILD_BUG_ON(sizeof(struct compat_vcpu_runstate_info) != 0x2c);
+
+ user_times = (uint64_t __user *)(ghc->hva +
+ offsetof(struct compat_vcpu_runstate_info,
+ state_entry_time));
+#ifdef CONFIG_X86_64
BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) !=
offsetof(struct compat_vcpu_runstate_info, state_entry_time) + 4);
BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, time) !=
offsetof(struct compat_vcpu_runstate_info, time) + 4);
if (v->kvm->arch.xen.long_mode)
- offset = offsetof(struct vcpu_runstate_info, state_entry_time);
+ user_times = (uint64_t __user *)(ghc->hva +
+ offsetof(struct vcpu_runstate_info,
+ state_entry_time));
#endif
/*
* First write the updated state_entry_time at the appropriate
@@ -172,10 +197,8 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
BUILD_BUG_ON(sizeof_field(struct compat_vcpu_runstate_info, state_entry_time) !=
sizeof(state_entry_time));
- if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
- &state_entry_time, offset,
- sizeof(state_entry_time)))
- return;
+ if (__put_user(state_entry_time, user_times))
+ goto out;
smp_wmb();
/*
@@ -189,11 +212,8 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
BUILD_BUG_ON(sizeof_field(struct compat_vcpu_runstate_info, state) !=
sizeof(vx->current_runstate));
- if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
- &vx->current_runstate,
- offsetof(struct vcpu_runstate_info, state),
- sizeof(vx->current_runstate)))
- return;
+ if (__put_user(vx->current_runstate, user_state))
+ goto out;
/*
* Write the actual runstate times immediately after the
@@ -208,24 +228,23 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, time) !=
sizeof(vx->runstate_times));
- if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
- &vx->runstate_times[0],
- offset + sizeof(u64),
- sizeof(vx->runstate_times)))
- return;
-
+ if (__copy_to_user(user_times + 1, vx->runstate_times, sizeof(vx->runstate_times)))
+ goto out;
smp_wmb();
/*
* Finally, clear the XEN_RUNSTATE_UPDATE bit in the guest's
* runstate_entry_time field.
*/
-
state_entry_time &= ~XEN_RUNSTATE_UPDATE;
- if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
- &state_entry_time, offset,
- sizeof(state_entry_time)))
- return;
+ __put_user(state_entry_time, user_times);
+ smp_wmb();
+
+ out:
+ mark_page_dirty_in_slot(v->kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
+
+ if (atomic)
+ pagefault_enable();
}
int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
@@ -443,6 +462,12 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
break;
}
+ /* It must fit within a single page */
+ if ((data->u.gpa & ~PAGE_MASK) + sizeof(struct vcpu_info) > PAGE_SIZE) {
+ r = -EINVAL;
+ break;
+ }
+
r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
&vcpu->arch.xen.vcpu_info_cache,
data->u.gpa,
@@ -460,6 +485,12 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
break;
}
+ /* It must fit within a single page */
+ if ((data->u.gpa & ~PAGE_MASK) + sizeof(struct pvclock_vcpu_time_info) > PAGE_SIZE) {
+ r = -EINVAL;
+ break;
+ }
+
r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
&vcpu->arch.xen.vcpu_time_info_cache,
data->u.gpa,
@@ -481,6 +512,12 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
break;
}
+ /* It must fit within a single page */
+ if ((data->u.gpa & ~PAGE_MASK) + sizeof(struct vcpu_runstate_info) > PAGE_SIZE) {
+ r = -EINVAL;
+ break;
+ }
+
r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
&vcpu->arch.xen.runstate_cache,
data->u.gpa,
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-27 12:15:21 +0000