@@ -361,6 +361,40 @@ static void reg_write(struct cpu_user_regs *regs,
*pval = value;
}
+static int operand_read(void *buf, struct vmx_inst_op *op,
+ struct cpu_user_regs *regs, unsigned int bytes)
+{
+ if ( op->type == VMX_INST_MEMREG_TYPE_REG )
+ {
+ switch ( bytes )
+ {
+ case 4:
+ *(uint32_t *)buf = reg_read(regs, op->reg_idx);
+
+ case 8:
+ *(uint64_t *)buf = reg_read(regs, op->reg_idx);
+
+ default:
+ ASSERT_UNREACHABLE();
+ return X86EMUL_UNHANDLEABLE;
+ }
+
+ return X86EMUL_OKAY;
+ }
+ else
+ {
+ pagefault_info_t pfinfo;
+ int rc = hvm_copy_from_guest_linear(buf, op->mem, bytes, 0, &pfinfo);
+
+ if ( rc == HVMTRANS_bad_linear_to_gfn )
+ hvm_inject_page_fault(pfinfo.ec, pfinfo.linear);
+ if ( rc != HVMTRANS_okay )
+ return X86EMUL_EXCEPTION;
+
+ return X86EMUL_OKAY;
+ }
+}
+
static inline u32 __n2_pin_exec_control(struct vcpu *v)
{
return get_vvmcs(v, PIN_BASED_VM_EXEC_CONTROL);
@@ -440,7 +474,12 @@ static int decode_vmx_inst(struct cpu_user_regs *regs,
decode->op[0].type = VMX_INST_MEMREG_TYPE_REG;
decode->op[0].reg_idx = info.fields.reg1;
if ( poperandS != NULL )
- *poperandS = reg_read(regs, decode->op[0].reg_idx);
+ {
+ int rc = operand_read(poperandS, &decode->op[0], regs,
+ decode->op[0].len);
+ if ( rc != X86EMUL_OKAY )
+ return rc;
+ }
}
else
{
@@ -475,20 +514,16 @@ static int decode_vmx_inst(struct cpu_user_regs *regs,
offset + size - 1 > seg.limit) )
goto gp_fault;
+ decode->op[0].mem = base;
+ decode->op[0].len = size;
+
if ( poperandS != NULL )
{
- pagefault_info_t pfinfo;
- int rc = hvm_copy_from_guest_linear(poperandS, base, size,
- 0, &pfinfo);
-
- if ( rc == HVMTRANS_bad_linear_to_gfn )
- hvm_inject_page_fault(pfinfo.ec, pfinfo.linear);
- if ( rc != HVMTRANS_okay )
- return X86EMUL_EXCEPTION;
+ int rc = operand_read(poperandS, &decode->op[0], regs,
+ decode->op[0].len);
+ if ( rc != X86EMUL_OKAY )
+ return rc;
}
-
- decode->op[0].mem = base;
- decode->op[0].len = size;
}
decode->op[1].type = VMX_INST_MEMREG_TYPE_REG;
Extract the logic for reading operands from decode_vmx_inst() into operand_read(). Future patches will replace operand reading logic in elsewhere with calls to operand_read(). operand_read() must explicitly handle different operand sizes to avoid corrupting the caller's stack. This patch should not change the overall behaviour of the code. Signed-off-by: Euan Harris <euan.harris@citrix.com> --- xen/arch/x86/hvm/vmx/vvmx.c | 59 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 47 insertions(+), 12 deletions(-)