On 03/06/2011 02:42 PM, Gleb Natapov wrote:
>
IO permission checking for 64-bit guest in KVM is wrong. The patch bellow
should fix it.
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 50ebc32..7ef5b86 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -142,10 +142,8 @@ struct x86_emulate_ops {
int (*pio_out_emulated)(int size, unsigned short port, const void *val,
unsigned int count, struct kvm_vcpu *vcpu);
- bool (*get_cached_descriptor)(struct desc_struct *desc,
- int seg, struct kvm_vcpu *vcpu);
- void (*set_cached_descriptor)(struct desc_struct *desc,
- int seg, struct kvm_vcpu *vcpu);
+ bool (*get_cached_descriptor)(void *p, int seg, struct kvm_vcpu *vcpu);
+ void (*set_cached_descriptor)(void *p, int seg, struct kvm_vcpu *vcpu);
Ugh, void *.
Add a u64 *highword parameter, or something.
@@ -1764,25 +1764,35 @@ static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops,
u16 port, u16 len)
{
- struct desc_struct tr_seg;
+ union {
+ struct desc_struct tss32;
+#ifdef CONFIG_X86_64
+ struct ldttss_desc64 tss64;
+#endif
+ } tr_seg;
int r;
u16 io_bitmap_ptr;
u8 perm, bit_idx = port& 0x7;
unsigned mask = (1<< len) - 1;
+ unsigned long base;
ops->get_cached_descriptor(&tr_seg, VCPU_SREG_TR, ctxt->vcpu);
- if (!tr_seg.p)
+ if (!tr_seg.tss32.p)
return false;
- if (desc_limit_scaled(&tr_seg)< 103)
+ if (desc_limit_scaled(&tr_seg.tss32)< 103)
return false;
- r = ops->read_std(get_desc_base(&tr_seg) + 102,&io_bitmap_ptr, 2,
- ctxt->vcpu, NULL);
+ base = get_desc_base(&tr_seg.tss32);
+#ifdef CONFIG_X86_64
+ if (ctxt->mode == X86EMUL_MODE_PROT64)
+ base |= ((u64)tr_seg.tss64.base3)<< 32;
+#endif
+ r = ops->read_std(base + 102,&io_bitmap_ptr, 2, ctxt->vcpu, NULL);
if (r != X86EMUL_CONTINUE)
return false;
Note: if we get a fault here, we ought to propagate it. Only happens if
there's a race, since the cpu checks for these exceptions.
--
error compiling committee.c: too many arguments to function
--
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