KVM: Cleanup string I/O instruction emulation
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>
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 436bdff..a83ff01 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -98,20 +98,6 @@
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 @@
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)
