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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
Download Patch File Download Diff File Expand all files Collapse all files
drivers/kvm/svm.c
+10 -139
View File
@@ -98,20 +98,6 @@ static inline u32 svm_has(u32 feat)
return svm_features & feat;
}
static unsigned get_addr_size(struct vcpu_svm *svm)
{
struct vmcb_save_area *sa = &svm->vmcb->save;
u16 cs_attrib;
if (!(sa->cr0 & X86_CR0_PE) || (sa->rflags & X86_EFLAGS_VM))
return 2;
cs_attrib = sa->cs.attrib;
return (cs_attrib & SVM_SELECTOR_L_MASK) ? 8 :
(cs_attrib & SVM_SELECTOR_DB_MASK) ? 4 : 2;
}
static inline u8 pop_irq(struct kvm_vcpu *vcpu)
{
int word_index = __ffs(vcpu->irq_summary);
@@ -995,147 +981,32 @@ static int shutdown_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
return 0;
}
static int io_get_override(struct vcpu_svm *svm,
struct vmcb_seg **seg,
int *addr_override)
{
u8 inst[MAX_INST_SIZE];
unsigned ins_length;
gva_t rip;
int i;
rip = svm->vmcb->save.rip;
ins_length = svm->next_rip - rip;
rip += svm->vmcb->save.cs.base;
if (ins_length > MAX_INST_SIZE)
printk(KERN_DEBUG
"%s: inst length err, cs base 0x%llx rip 0x%llx "
"next rip 0x%llx ins_length %u\n",
__FUNCTION__,
svm->vmcb->save.cs.base,
svm->vmcb->save.rip,
svm->vmcb->control.exit_info_2,
ins_length);
if (emulator_read_std(rip, inst, ins_length, &svm->vcpu)
!= X86EMUL_CONTINUE)
/* #PF */
return 0;
*addr_override = 0;
*seg = NULL;
for (i = 0; i < ins_length; i++)
switch (inst[i]) {
case 0xf0:
case 0xf2:
case 0xf3:
case 0x66:
continue;
case 0x67:
*addr_override = 1;
continue;
case 0x2e:
*seg = &svm->vmcb->save.cs;
continue;
case 0x36:
*seg = &svm->vmcb->save.ss;
continue;
case 0x3e:
*seg = &svm->vmcb->save.ds;
continue;
case 0x26:
*seg = &svm->vmcb->save.es;
continue;
case 0x64:
*seg = &svm->vmcb->save.fs;
continue;
case 0x65:
*seg = &svm->vmcb->save.gs;
continue;
default:
return 1;
}
printk(KERN_DEBUG "%s: unexpected\n", __FUNCTION__);
return 0;
}
static unsigned long io_address(struct vcpu_svm *svm, int ins, gva_t *address)
{
unsigned long addr_mask;
unsigned long *reg;
struct vmcb_seg *seg;
int addr_override;
struct vmcb_save_area *save_area = &svm->vmcb->save;
u16 cs_attrib = save_area->cs.attrib;
unsigned addr_size = get_addr_size(svm);
if (!io_get_override(svm, &seg, &addr_override))
return 0;
if (addr_override)
addr_size = (addr_size == 2) ? 4: (addr_size >> 1);
if (ins) {
reg = &svm->vcpu.regs[VCPU_REGS_RDI];
seg = &svm->vmcb->save.es;
} else {
reg = &svm->vcpu.regs[VCPU_REGS_RSI];
seg = (seg) ? seg : &svm->vmcb->save.ds;
}
addr_mask = ~0ULL >> (64 - (addr_size * 8));
if ((cs_attrib & SVM_SELECTOR_L_MASK) &&
!(svm->vmcb->save.rflags & X86_EFLAGS_VM)) {
*address = (*reg & addr_mask);
return addr_mask;
}
if (!(seg->attrib & SVM_SELECTOR_P_SHIFT)) {
svm_inject_gp(&svm->vcpu, 0);
return 0;
}
*address = (*reg & addr_mask) + seg->base;
return addr_mask;
}
static int io_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
{
u32 io_info = svm->vmcb->control.exit_info_1; //address size bug?
int size, down, in, string, rep;
unsigned port;
unsigned long count;
gva_t address = 0;
++svm->vcpu.stat.io_exits;
svm->next_rip = svm->vmcb->control.exit_info_2;
string = (io_info & SVM_IOIO_STR_MASK) != 0;
if (string) {
if (emulate_instruction(&svm->vcpu, kvm_run, 0, 0) == EMULATE_DO_MMIO)
return 0;
return 1;
}
in = (io_info & SVM_IOIO_TYPE_MASK) != 0;
port = io_info >> 16;
size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT;
string = (io_info & SVM_IOIO_STR_MASK) != 0;
rep = (io_info & SVM_IOIO_REP_MASK) != 0;
count = 1;
down = (svm->vmcb->save.rflags & X86_EFLAGS_DF) != 0;
if (string) {
unsigned addr_mask;
addr_mask = io_address(svm, in, &address);
if (!addr_mask) {
printk(KERN_DEBUG "%s: get io address failed\n",
__FUNCTION__);
return 1;
}
if (rep)
count = svm->vcpu.regs[VCPU_REGS_RCX] & addr_mask;
}
return kvm_setup_pio(&svm->vcpu, kvm_run, in, size, count, string,
down, address, rep, port);
return kvm_setup_pio(&svm->vcpu, kvm_run, in, size, 1, 0,
down, 0, rep, port);
}
static int nop_on_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)