Commit 6fd8e127 authored by Nadav Amit's avatar Nadav Amit Committed by Paolo Bonzini
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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: default avatarNadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427719163-5429-3-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent b91aa14d

arch/x86/kvm/emulate.c

+23 −16
Original line number Diff line number Diff line
@@ -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;

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