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Fix a couple of issues in the PUSH emulation:

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It is not possible to PUSH a 32-bit operand on the stack in 64-bit mode. The
default operand size for PUSH is 64-bits and the operand size override prefix
changes that to 16-bits.

vm_copy_setup() can return '1' if it encounters a fault when walking the
guest page tables. This is a guest issue and is now handled properly by
resuming the guest to handle the fault.
This commit is contained in:
Neel Natu 2014-07-24 23:01:53 +00:00
parent 0708297e43
commit 830be8acb4
1 changed files with 15 additions and 5 deletions
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20
sys/amd64/vmm/vmm_instruction_emul.c
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@ -726,11 +726,19 @@ emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
/*
* From "Address-Size Attributes for Stack Accesses", Intel SDL, Vol 1
*/
if (paging->cpu_mode == CPU_MODE_REAL)
if (paging->cpu_mode == CPU_MODE_REAL) {
stackaddrsize = 2;
else if (paging->cpu_mode == CPU_MODE_64BIT)
} else if (paging->cpu_mode == CPU_MODE_64BIT) {
/*
* "Stack Manipulation Instructions in 64-bit Mode", SDM, Vol 3
* - Stack pointer size is always 64-bits.
* - PUSH/POP of 32-bit values is not possible in 64-bit mode.
* - 16-bit PUSH/POP is supported by using the operand size
* override prefix (66H).
*/
stackaddrsize = 8;
else {
size = vie->opsize_override ? 2 : 8;
} else {
/*
* In protected or compability mode the 'B' flag in the
* stack-segment descriptor determines the size of the
@ -773,8 +781,10 @@ emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
error = vm_copy_setup(vm, vcpuid, paging, stack_gla, size, PROT_WRITE,
copyinfo, nitems(copyinfo));
if (error)
return (error);
if (error == -1)
return (-1); /* Unrecoverable error */
else if (error == 1)
return (0); /* Return to guest to handle page fault */
error = memread(vm, vcpuid, mmio_gpa, &val, size, arg);
if (error == 0) {