in/out emulation is broken now. The breakage is different depending
on where IO device resides. If it is in userspace emulator reports
emulation failure since it incorrectly interprets kvm_emulate_pio()
return value. If IO device is in the kernel emulation of 'in' will do
nothing since kvm_emulate_pio() stores result directly into vcpu
registers, so emulator will overwrite result of emulation during
commit of shadowed register.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_emulate.h | 7 +
arch/x86/include/asm/kvm_host.h | 3 +-
arch/x86/kvm/emulate.c | 47 ++++-----
arch/x86/kvm/svm.c | 20 +--
arch/x86/kvm/vmx.c | 20 ++--
arch/x86/kvm/x86.c | 213 ++++++++++++++++++++++--------------
6 files changed, 176 insertions(+), 134 deletions(-)
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index bd46929..679245c 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -119,6 +119,13 @@ struct x86_emulate_ops {
const void *new,
unsigned int bytes,
struct kvm_vcpu *vcpu);
+
+ int (*pio_in_emulated)(int size, unsigned short port, void *val,
+ unsigned int count, struct kvm_vcpu *vcpu);
+
+ int (*pio_out_emulated)(int size, unsigned short port, const void *val,
+ unsigned int count, struct kvm_vcpu *vcpu);
+
bool (*get_cached_descriptor)(struct desc_struct *desc,
int seg, struct kvm_vcpu *vcpu);
void (*set_cached_descriptor)(struct desc_struct *desc,
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1e15a0a..6f7ad5c 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -589,8 +589,7 @@ int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
struct x86_emulate_ctxt;
-int kvm_emulate_pio(struct kvm_vcpu *vcpu, int in,
- int size, unsigned port);
+int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port);
int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, int in,
int size, unsigned long count, int down,
gva_t address, int rep, unsigned port);
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 8f5e4c8..344e17b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -210,13 +210,13 @@ static u32 opcode_table[256] = {
0, 0, 0, 0, 0, 0, 0, 0,
/* 0xE0 - 0xE7 */
0, 0, 0, 0,
- ByteOp | SrcImmUByte, SrcImmUByte,
- ByteOp | SrcImmUByte, SrcImmUByte,
+ ByteOp | SrcImmUByte | DstAcc, SrcImmUByte | DstAcc,
+ ByteOp | SrcImmUByte | DstAcc, SrcImmUByte | DstAcc,
/* 0xE8 - 0xEF */
SrcImm | Stack, SrcImm | ImplicitOps,
SrcImmU | Src2Imm16 | No64, SrcImmByte | ImplicitOps,
- SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps,
- SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps,
+ SrcNone | ByteOp | DstAcc, SrcNone | DstAcc,
+ SrcNone | ByteOp | DstAcc, SrcNone | DstAcc,
/* 0xF0 - 0xF7 */
0, 0, 0, 0,
ImplicitOps | Priv, ImplicitOps, Group | Group3_Byte, Group | Group3,
@@ -2414,8 +2414,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
u64 msr_data;
unsigned long saved_eip = 0;
struct decode_cache *c = &ctxt->decode;
- unsigned int port;
- int io_dir_in;
int rc = X86EMUL_CONTINUE;
ctxt->interruptibility = 0;
@@ -2814,14 +2812,10 @@ special_insn:
break;
case 0xe4: /* inb */
case 0xe5: /* in */
- port = c->src.val;
- io_dir_in = 1;
- goto do_io;
+ goto do_io_in;
case 0xe6: /* outb */
case 0xe7: /* out */
- port = c->src.val;
- io_dir_in = 0;
- goto do_io;
+ goto do_io_out;
case 0xe8: /* call (near) */ {
long int rel = c->src.val;
c->src.val = (unsigned long) c->eip;
@@ -2846,25 +2840,26 @@ special_insn:
break;
case 0xec: /* in al,dx */
case 0xed: /* in (e/r)ax,dx */
- port = c->regs[VCPU_REGS_RDX];
- io_dir_in = 1;
- goto do_io;
+ c->src.val = c->regs[VCPU_REGS_RDX];
+ do_io_in:
+ if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {
+ kvm_inject_gp(ctxt->vcpu, 0);
+ goto done;
+ }
+ ops->pio_in_emulated(c->dst.bytes, c->src.val, &c->dst.val, 1,
+ ctxt->vcpu);
+ break;
case 0xee: /* out al,dx */
case 0xef: /* out (e/r)ax,dx */
- port = c->regs[VCPU_REGS_RDX];
- io_dir_in = 0;
- do_io:
- if (!emulator_io_permited(ctxt, ops, port,
- (c->d & ByteOp) ? 1 : c->op_bytes)) {
+ c->src.val = c->regs[VCPU_REGS_RDX];
+ do_io_out:
+ if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {
kvm_inject_gp(ctxt->vcpu, 0);
goto done;
}
- if (kvm_emulate_pio(ctxt->vcpu, io_dir_in,
- (c->d & ByteOp) ? 1 : c->op_bytes,
- port) != 0) {
- c->eip = saved_eip;
- goto cannot_emulate;
- }
+ ops->pio_out_emulated(c->dst.bytes, c->src.val, &c->dst.val, 1,
+ ctxt->vcpu);
+ c->dst.type = OP_NONE; /* Disable writeback. */
break;
case 0xf4: /* hlt */
ctxt->vcpu->arch.halt_request = 1;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b646e96..2a49310 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1493,29 +1493,23 @@ static int shutdown_interception(struct vcpu_svm *svm)
static int io_interception(struct vcpu_svm *svm)
{
+ struct kvm_vcpu *vcpu = &svm->vcpu;
u32 io_info = svm->vmcb->control.exit_info_1; /* address size bug? */
int size, in, string;
unsigned port;
++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,
- 0, 0, 0) == EMULATE_DO_MMIO)
- return 0;
- return 1;
- }
-
in = (io_info & SVM_IOIO_TYPE_MASK) != 0;
+ if (string || in)
+ return !(emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO);
+
port = io_info >> 16;
size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT;
+ svm->next_rip = svm->vmcb->control.exit_info_2;
+ skip_emulated_instruction(&svm->vcpu);
- skip_emulated_instruction(&svm->vcpu);
- return kvm_emulate_pio(&svm->vcpu, in, size, port);
+ return kvm_fast_pio_out(vcpu, size, port);
}
static int nmi_interception(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 06108f3..1042324 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2977,23 +2977,21 @@ static int handle_io(struct kvm_vcpu *vcpu)
unsigned long exit_qualification;
int size, in, string;
unsigned port;
-
- ++vcpu->stat.io_exits;
+
exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
string = (exit_qualification & 16) != 0;
+ in = (exit_qualification & 8) != 0;
- if (string) {
- if (emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO)
- return 0;
- return 1;
- }
+ ++vcpu->stat.io_exits;
- size = (exit_qualification & 7) + 1;
- in = (exit_qualification & 8) != 0;
- port = exit_qualification >> 16;
+ if (string || in)
+ return !(emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO);
+ port = exit_qualification >> 16;
+ size = (exit_qualification & 7) + 1;
skip_emulated_instruction(vcpu);
- return kvm_emulate_pio(vcpu, in, size, port);
+
+ return kvm_fast_pio_out(vcpu, size, port);
}
static void
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3c5ffa2..37c6178 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3351,6 +3351,86 @@ emul_write:
return emulator_write_emulated(addr, new, bytes, vcpu);
}
+static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
+{
+ /* TODO: String I/O for in kernel device */
+ int r;
+
+ if (vcpu->arch.pio.in)
+ r = kvm_io_bus_read(vcpu->kvm, KVM_PIO_BUS, vcpu->arch.pio.port,
+ vcpu->arch.pio.size, pd);
+ else
+ r = kvm_io_bus_write(vcpu->kvm, KVM_PIO_BUS,
+ vcpu->arch.pio.port, vcpu->arch.pio.size,
+ pd);
+ return r;
+}
+
+
+static int emulator_pio_in_emulated(int size, unsigned short port, void *val,
+ unsigned int count, struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.pio.cur_count)
+ goto data_avail;
+
+ trace_kvm_pio(1, port, size, 1);
+
+ vcpu->arch.pio.port = port;
+ vcpu->arch.pio.in = 1;
+ vcpu->arch.pio.string = 0;
+ vcpu->arch.pio.down = 0;
+ vcpu->arch.pio.rep = 0;
+ vcpu->arch.pio.count = vcpu->arch.pio.cur_count = count;
+ vcpu->arch.pio.size = size;
+
+ if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
+ data_avail:
+ memcpy(val, vcpu->arch.pio_data, size * count);
+ vcpu->arch.pio.cur_count = 0;
+ return 1;
+ }
+
+ vcpu->run->exit_reason = KVM_EXIT_IO;
+ vcpu->run->io.direction = KVM_EXIT_IO_IN;
+ vcpu->run->io.size = size;
+ vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
+ vcpu->run->io.count = count;
+ vcpu->run->io.port = port;
+
+ return 0;
+}
+
+static int emulator_pio_out_emulated(int size, unsigned short port,
+ const void *val, unsigned int count,
+ struct kvm_vcpu *vcpu)
+{
+ trace_kvm_pio(0, port, size, 1);
+
+ vcpu->arch.pio.port = port;
+ vcpu->arch.pio.in = 0;
+ vcpu->arch.pio.string = 0;
+ vcpu->arch.pio.down = 0;
+ vcpu->arch.pio.rep = 0;
+ vcpu->arch.pio.count = vcpu->arch.pio.cur_count = count;
+ vcpu->arch.pio.size = size;
+
+ memcpy(vcpu->arch.pio_data, val, size * count);
+
+ if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
+ vcpu->arch.pio.cur_count = 0;
+ return 1;
+ }
+
+ vcpu->run->exit_reason = KVM_EXIT_IO;
+ vcpu->run->io.direction = KVM_EXIT_IO_OUT;
+ vcpu->run->io.size = size;
+ vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
+ vcpu->run->io.count = count;
+ vcpu->run->io.port = port;
+
+ return 0;
+}
+
static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
return kvm_x86_ops->get_segment_base(vcpu, seg);
@@ -3544,6 +3624,8 @@ static struct x86_emulate_ops emulate_ops = {
.read_emulated = emulator_read_emulated,
.write_emulated = emulator_write_emulated,
.cmpxchg_emulated = emulator_cmpxchg_emulated,
+ .pio_in_emulated = emulator_pio_in_emulated,
+ .pio_out_emulated = emulator_pio_out_emulated,
.get_cached_descriptor = emulator_get_cached_descriptor,
.set_cached_descriptor = emulator_set_cached_descriptor,
.get_segment_selector = emulator_get_segment_selector,
@@ -3651,6 +3733,12 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
if (vcpu->arch.pio.string)
return EMULATE_DO_MMIO;
+ if (vcpu->arch.pio.cur_count && !vcpu->arch.pio.string) {
+ if (!vcpu->arch.pio.in)
+ vcpu->arch.pio.cur_count = 0;
+ return EMULATE_DO_MMIO;
+ }
+
if (r || vcpu->mmio_is_write) {
run->exit_reason = KVM_EXIT_MMIO;
run->mmio.phys_addr = vcpu->mmio_phys_addr;
@@ -3707,43 +3795,36 @@ int complete_pio(struct kvm_vcpu *vcpu)
int r;
unsigned long val;
- if (!io->string) {
- if (io->in) {
- val = kvm_register_read(vcpu, VCPU_REGS_RAX);
- memcpy(&val, vcpu->arch.pio_data, io->size);
- kvm_register_write(vcpu, VCPU_REGS_RAX, val);
- }
- } else {
- if (io->in) {
- r = pio_copy_data(vcpu);
- if (r)
- goto out;
- }
+ if (io->in) {
+ r = pio_copy_data(vcpu);
+ if (r)
+ goto out;
+ }
- delta = 1;
- if (io->rep) {
- delta *= io->cur_count;
- /*
- * The size of the register should really depend on
- * current address size.
- */
- val = kvm_register_read(vcpu, VCPU_REGS_RCX);
- val -= delta;
- kvm_register_write(vcpu, VCPU_REGS_RCX, val);
- }
- if (io->down)
- delta = -delta;
- delta *= io->size;
- if (io->in) {
- val = kvm_register_read(vcpu, VCPU_REGS_RDI);
- val += delta;
- kvm_register_write(vcpu, VCPU_REGS_RDI, val);
- } else {
- val = kvm_register_read(vcpu, VCPU_REGS_RSI);
- val += delta;
- kvm_register_write(vcpu, VCPU_REGS_RSI, val);
- }
+ delta = 1;
+ if (io->rep) {
+ delta *= io->cur_count;
+ /*
+ * The size of the register should really depend on
+ * current address size.
+ */
+ val = kvm_register_read(vcpu, VCPU_REGS_RCX);
+ val -= delta;
+ kvm_register_write(vcpu, VCPU_REGS_RCX, val);
+ }
+ if (io->down)
+ delta = -delta;
+ delta *= io->size;
+ if (io->in) {
+ val = kvm_register_read(vcpu, VCPU_REGS_RDI);
+ val += delta;
+ kvm_register_write(vcpu, VCPU_REGS_RDI, val);
+ } else {
+ val = kvm_register_read(vcpu, VCPU_REGS_RSI);
+ val += delta;
+ kvm_register_write(vcpu, VCPU_REGS_RSI, val);
}
+
out:
io->count -= io->cur_count;
io->cur_count = 0;
@@ -3751,21 +3832,6 @@ out:
return 0;
}
-static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
-{
- /* TODO: String I/O for in kernel device */
- int r;
-
- if (vcpu->arch.pio.in)
- r = kvm_io_bus_read(vcpu->kvm, KVM_PIO_BUS, vcpu->arch.pio.port,
- vcpu->arch.pio.size, pd);
- else
- r = kvm_io_bus_write(vcpu->kvm, KVM_PIO_BUS,
- vcpu->arch.pio.port, vcpu->arch.pio.size,
- pd);
- return r;
-}
-
static int pio_string_write(struct kvm_vcpu *vcpu)
{
struct kvm_pio_request *io = &vcpu->arch.pio;
@@ -3783,36 +3849,6 @@ static int pio_string_write(struct kvm_vcpu *vcpu)
return r;
}
-int kvm_emulate_pio(struct kvm_vcpu *vcpu, int in, int size, unsigned port)
-{
- unsigned long val;
-
- trace_kvm_pio(!in, port, size, 1);
-
- vcpu->run->exit_reason = KVM_EXIT_IO;
- vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
- vcpu->run->io.size = vcpu->arch.pio.size = size;
- vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
- vcpu->run->io.count = vcpu->arch.pio.count = vcpu->arch.pio.cur_count = 1;
- vcpu->run->io.port = vcpu->arch.pio.port = port;
- vcpu->arch.pio.in = in;
- vcpu->arch.pio.string = 0;
- vcpu->arch.pio.down = 0;
- vcpu->arch.pio.rep = 0;
-
- if (!vcpu->arch.pio.in) {
- val = kvm_register_read(vcpu, VCPU_REGS_RAX);
- memcpy(vcpu->arch.pio_data, &val, 4);
- }
-
- if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
- complete_pio(vcpu);
- return 1;
- }
- return 0;
-}
-EXPORT_SYMBOL_GPL(kvm_emulate_pio);
-
int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, int in,
int size, unsigned long count, int down,
gva_t address, int rep, unsigned port)
@@ -3878,6 +3914,16 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, int in,
}
EXPORT_SYMBOL_GPL(kvm_emulate_pio_string);
+int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port)
+{
+ unsigned long val = kvm_register_read(vcpu, VCPU_REGS_RAX);
+ int ret = emulator_pio_out_emulated(size, port, &val, 1, vcpu);
+ /* do not return to emulator after return from userspace */
+ vcpu->arch.pio.count = 0;
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_fast_pio_out);
+
static void bounce_off(void *info)
{
/* nothing */
@@ -4608,9 +4654,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (vcpu->arch.pio.cur_count) {
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
- r = complete_pio(vcpu);
+ if (!vcpu->arch.pio.string)
+ r = emulate_instruction(vcpu, 0, 0, EMULTYPE_NO_DECODE);
+ else
+ r = complete_pio(vcpu);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
- if (r)
+ if (r == EMULATE_DO_MMIO)
goto out;
}
if (vcpu->mmio_needed) {
--
1.6.5
--
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