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KVM: Cleanup string I/O instruction emulation

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Both vmx and svm decode the I/O instructions, and both botch the job,
requiring the instruction prefixes to be fetched in order to completely
decode the instruction.

So, if we see a string I/O instruction, use the x86 emulator to decode it,
as it already has all the prefix decoding machinery.

This patch defines ins/outs opcodes in x86_emulate.c and calls
emulate_instruction() from io_interception() (svm.c) and from handle_io()
(vmx.c).  It removes all vmx/svm prefix instruction decoders
(get_addr_size(), io_get_override(), io_address(), get_io_count())

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Laurent Vivier
2007-08-05 10:36:40 +03:00
committed by Avi Kivity
parent 9fdaaac38e
commit e70669abd4
4 changed files with 69 additions and 208 deletions
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76
drivers/kvm/vmx.c
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@@ -1763,82 +1763,30 @@ static int handle_triple_fault(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
return 0;
}
static int get_io_count(struct kvm_vcpu *vcpu, unsigned long *count)
{
u64 inst;
gva_t rip;
int countr_size;
int i;
if ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_VM)) {
countr_size = 2;
} else {
u32 cs_ar = vmcs_read32(GUEST_CS_AR_BYTES);
countr_size = (cs_ar & AR_L_MASK) ? 8:
(cs_ar & AR_DB_MASK) ? 4: 2;
}
rip = vmcs_readl(GUEST_RIP);
if (countr_size != 8)
rip += vmcs_readl(GUEST_CS_BASE);
if (emulator_read_std(rip, &inst, sizeof(inst), vcpu) !=
X86EMUL_CONTINUE)
return 0;
for (i = 0; i < sizeof(inst); i++) {
switch (((u8*)&inst)[i]) {
case 0xf0:
case 0xf2:
case 0xf3:
case 0x2e:
case 0x36:
case 0x3e:
case 0x26:
case 0x64:
case 0x65:
case 0x66:
break;
case 0x67:
countr_size = (countr_size == 2) ? 4: (countr_size >> 1);
default:
goto done;
}
}
return 0;
done:
countr_size *= 8;
*count = vcpu->regs[VCPU_REGS_RCX] & (~0ULL >> (64 - countr_size));
//printk("cx: %lx\n", vcpu->regs[VCPU_REGS_RCX]);
return 1;
}
static int handle_io(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
u64 exit_qualification;
int size, down, in, string, rep;
unsigned port;
unsigned long count;
gva_t address;
++vcpu->stat.io_exits;
exit_qualification = vmcs_read64(EXIT_QUALIFICATION);
in = (exit_qualification & 8) != 0;
size = (exit_qualification & 7) + 1;
string = (exit_qualification & 16) != 0;
if (string) {
if (emulate_instruction(vcpu, kvm_run, 0, 0) == EMULATE_DO_MMIO)
return 0;
return 1;
}
size = (exit_qualification & 7) + 1;
in = (exit_qualification & 8) != 0;
down = (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_DF) != 0;
count = 1;
rep = (exit_qualification & 32) != 0;
port = exit_qualification >> 16;
address = 0;
if (string) {
if (rep && !get_io_count(vcpu, &count))
return 1;
address = vmcs_readl(GUEST_LINEAR_ADDRESS);
}
return kvm_setup_pio(vcpu, kvm_run, in, size, count, string, down,
address, rep, port);
return kvm_setup_pio(vcpu, kvm_run, in, size, 1, 0, down,
0, rep, port);
}
static void