[PATCH] KVM: nSVM: Set correct port for IOIO interception evaluation

Jan Kiszka
2014-06-30T10:53:04Z

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From: Jan Kiszka <jan.kiszka@siemens.com>

Obtaining the port number from DX is bogus as a) there are immediate
port accesses and b) user space may have changed the register content
while processing the PIO access. Forward the correct value from the
instruction emulator instead.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

Valentine, I've a stable Jailhouse root cell under QEMU now :)

arch/x86/include/asm/kvm_emulate.h | 1 +
arch/x86/kvm/emulate.c | 1 +
arch/x86/kvm/svm.c | 6 +++---
3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index ffa2671..0e0151c 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -37,6 +37,7 @@ struct x86_instruction_info {
u8 modrm_reg; /* index of register used */
u8 modrm_rm; /* rm part of modrm */
u64 src_val; /* value of source operand */
+ u64 dst_val; /* value of destination operand */
u8 src_bytes; /* size of source operand */
u8 dst_bytes; /* size of destination operand */
u8 ad_bytes; /* size of src/dst address */
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 84dc4ba..15453e5 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -426,6 +426,7 @@ static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
.modrm_reg = ctxt->modrm_reg,
.modrm_rm = ctxt->modrm_rm,
.src_val = ctxt->src.val64,
+ .dst_val = ctxt->dst.val64,
.src_bytes = ctxt->src.bytes,
.dst_bytes = ctxt->dst.bytes,
.ad_bytes = ctxt->ad_bytes,
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1824949..85d4458 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4256,13 +4256,13 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
u64 exit_info;
u32 bytes;

- exit_info = (vcpu->arch.regs[VCPU_REGS_RDX] & 0xffff) << 16;
-
if (info->intercept == x86_intercept_in ||
info->intercept == x86_intercept_ins) {
- exit_info |= SVM_IOIO_TYPE_MASK;
+ exit_info = ((info->src_val & 0xffff) << 16) |
+ SVM_IOIO_TYPE_MASK;
bytes = info->dst_bytes;
} else {
+ exit_info = (info->dst_val & 0xffff) << 16;
bytes = info->src_bytes;
}

--
1.8.4.5