hv: extend the decode_modrm

If rm show there is no SIB following rm field, we should get
base_register info from rm.

Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
This commit is contained in:
Yin Fengwei 2018-08-13 14:42:50 +08:00 committed by lijinxia
parent 3b6ccf0c91
commit 5663dd7d14

View File

@ -1636,6 +1636,11 @@ static int vie_init(struct instr_emul_vie *vie, struct vcpu *vcpu)
(void)memset(vie, 0U, sizeof(struct instr_emul_vie));
/* init register fields in vie. */
vie->base_register = CPU_REG_LAST;
vie->index_register = CPU_REG_LAST;
vie->segment_register = CPU_REG_LAST;
err_code = PAGE_FAULT_ID_FLAG;
ret = copy_from_gva(vcpu, vie->inst, guest_rip_gva,
inst_len, &err_code, &fault_addr);
@ -1859,6 +1864,42 @@ static int decode_modrm(struct instr_emul_vie *vie, enum vm_cpu_mode cpu_mode)
vie->reg |= (vie->rex_r << 3);
/* SIB */
if (vie->mod != VIE_MOD_DIRECT && vie->rm == VIE_RM_SIB) {
goto done;
}
vie->base_register = vie->rm;
switch (vie->mod) {
case VIE_MOD_INDIRECT_DISP8:
vie->disp_bytes = 1U;
break;
case VIE_MOD_INDIRECT_DISP32:
vie->disp_bytes = 4U;
break;
case VIE_MOD_INDIRECT:
if (vie->rm == VIE_RM_DISP32) {
vie->disp_bytes = 4U;
/*
* Table 2-7. RIP-Relative Addressing
*
* In 64-bit mode mod=00 r/m=101 implies [rip] + disp32
* whereas in compatibility mode it just implies disp32.
*/
if (cpu_mode == CPU_MODE_64BIT) {
vie->base_register = CPU_REG_RIP;
pr_err("VM exit with RIP as indirect access");
}
else {
vie->base_register = CPU_REG_LAST;
}
}
break;
}
done:
vie_advance(vie);
return 0;
@ -1935,7 +1976,7 @@ static int decode_sib(struct instr_emul_vie *vie)
}
/* 'scale' makes sense only in the context of an index register */
if (vie->index_register <= CPU_REG_LAST) {
if (vie->index_register < CPU_REG_LAST) {
vie->scale = 1U << vie->ss;
}