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authorNadav Amit <namit@cs.technion.ac.il>2015-03-30 15:39:20 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2015-03-30 16:46:03 +0200
commit6fd8e1275709a5bb084847eda6730b983538a572 (patch)
treeac9bd3385ff16bb9b64b1abadd957bbe64b9d184 /arch/x86/kvm/emulate.c
parentb91aa14d95bf4cf8ed0426bd25c0af1548519696 (diff)
KVM: x86: POPA emulation may not clear bits [63:32]
POPA should assign the values to the registers as usual registers are assigned. In other words, 32-bits register assignments should clear bits [63:32] of the register. Split the code of register assignments that will be used by future changes as well. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427719163-5429-3-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
-rw-r--r--arch/x86/kvm/emulate.c39
1 files changed, 23 insertions, 16 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 62f7a395717d..4961dc5eb303 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -478,6 +478,25 @@ static void assign_masked(ulong *dest, ulong src, ulong mask)
*dest = (*dest & ~mask) | (src & mask);
}
+static void assign_register(unsigned long *reg, u64 val, int bytes)
+{
+ /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
+ switch (bytes) {
+ case 1:
+ *(u8 *)reg = (u8)val;
+ break;
+ case 2:
+ *(u16 *)reg = (u16)val;
+ break;
+ case 4:
+ *reg = (u32)val;
+ break; /* 64b: zero-extend */
+ case 8:
+ *reg = val;
+ break;
+ }
+}
+
static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt)
{
return (1UL << (ctxt->ad_bytes << 3)) - 1;
@@ -1691,21 +1710,7 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
static void write_register_operand(struct operand *op)
{
- /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
- switch (op->bytes) {
- case 1:
- *(u8 *)op->addr.reg = (u8)op->val;
- break;
- case 2:
- *(u16 *)op->addr.reg = (u16)op->val;
- break;
- case 4:
- *op->addr.reg = (u32)op->val;
- break; /* 64b: zero-extend */
- case 8:
- *op->addr.reg = op->val;
- break;
- }
+ return assign_register(op->addr.reg, op->val, op->bytes);
}
static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op)
@@ -1926,6 +1931,7 @@ static int em_popa(struct x86_emulate_ctxt *ctxt)
{
int rc = X86EMUL_CONTINUE;
int reg = VCPU_REGS_RDI;
+ u32 val;
while (reg >= VCPU_REGS_RAX) {
if (reg == VCPU_REGS_RSP) {
@@ -1933,9 +1939,10 @@ static int em_popa(struct x86_emulate_ctxt *ctxt)
--reg;
}
- rc = emulate_pop(ctxt, reg_rmw(ctxt, reg), ctxt->op_bytes);
+ rc = emulate_pop(ctxt, &val, ctxt->op_bytes);
if (rc != X86EMUL_CONTINUE)
break;
+ assign_register(reg_rmw(ctxt, reg), val, ctxt->op_bytes);
--reg;
}
return rc;