Prepare for subsequent changes. Extract calls for segment checking in protected
and 64-bit mode. This should be done to avoid overbloating of
get_vmx_mem_address() function, even if kvm_queue_exception_e() is called
twice.
Signed-off-by: Eugene Korenevsky <ekorenevsky@xxxxxxxxx>
---
arch/x86/kvm/vmx.c | 106 +++++++++++++++++++++++++++++------------------------
1 file changed, 59 insertions(+), 47 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index da1590e..32d2979 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6335,6 +6335,59 @@ static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer)
return HRTIMER_NORESTART;
}
+/* Long mode: #GP(0)/#SS(0) if the memory address is in
+ * a non-canonical form.
+ */
+static int vmx_longmode_seg_check(struct kvm_vcpu *vcpu, int seg_reg, gva_t la)
+{
+ if (is_noncanonical_address(la)) {
+ kvm_queue_exception_e(vcpu,
+ seg_reg == VCPU_SREG_SS ?
+ SS_VECTOR : GP_VECTOR,
+ 0);
+ return 1;
+ }
+ return 0;
+}
+
+/* Protected mode: apply checks for segment validity in the following order:
+ * - segment type check (#GP(0) may be thrown)
+ * - usability check (#GP(0)/#SS(0))
+ * - limit check (#GP(0)/#SS(0))
+ */
+static int vmx_protmode_seg_check(struct kvm_vcpu *vcpu,
+ int seg, const struct kvm_segment *s,
+ bool wr, int mem_op_size, gva_t off)
+{
+ bool exn;
+
+ /* #GP(0) if the destination operand is located in a read-only data
+ * segment or any code segment.
+ * #GP(0) if the source operand is located in an execute-only code
+ * segment.
+ */
+ if (wr)
+ exn = ((s->type & 0xa) == 0 || (s->type & 8));
+ else
+ exn = ((s->type & 0xa) == 8);
+ if (exn) {
+ kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
+ return 1;
+ }
+ /* #GP(0)/#SS(0) if the segment is unusable. */
+ exn = (s->unusable != 0);
+ /* #GP(0)/#SS(0) if the memory operand is outside the segment limit. */
+ exn = exn || (off + mem_op_size > s->limit);
+ if (exn) {
+ kvm_queue_exception_e(vcpu,
+ seg == VCPU_SREG_SS ?
+ SS_VECTOR : GP_VECTOR,
+ 0);
+ return 1;
+ }
+ return 0;
+}
+
/*
* Decode the memory-address operand of a vmx instruction, as recorded on an
* exit caused by such an instruction (run by a guest hypervisor).
@@ -6346,7 +6399,6 @@ static int get_vmx_mem_address(struct kvm_vcpu *vcpu,
u32 vmx_instruction_info, bool wr, gva_t *ret)
{
gva_t off;
- bool exn;
struct kvm_segment s;
/*
@@ -6381,55 +6433,15 @@ static int get_vmx_mem_address(struct kvm_vcpu *vcpu,
vmx_get_segment(vcpu, &s, seg_reg);
*ret = s.base + off;
+ if (is_long_mode(vcpu))
+ return vmx_longmode_seg_check(vcpu, seg_reg, *ret);
+
if (addr_size == 1) /* 32 bit */
*ret &= 0xffffffff;
- /* Checks for #GP/#SS exceptions. */
- exn = false;
- if (is_protmode(vcpu)) {
- /* Protected mode: apply checks for segment validity in the
- * following order:
- * - segment type check (#GP(0) may be thrown)
- * - usability check (#GP(0)/#SS(0))
- * - limit check (#GP(0)/#SS(0))
- */
- if (wr)
- /* #GP(0) if the destination operand is located in a
- * read-only data segment or any code segment.
- */
- exn = ((s.type & 0xa) == 0 || (s.type & 8));
- else
- /* #GP(0) if the source operand is located in an
- * execute-only code segment
- */
- exn = ((s.type & 0xa) == 8);
- }
- if (exn) {
- kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
- return 1;
- }
- if (is_long_mode(vcpu)) {
- /* Long mode: #GP(0)/#SS(0) if the memory address is in a
- * non-canonical form. This is an only check for long mode.
- */
- exn = is_noncanonical_address(*ret);
- } else if (is_protmode(vcpu)) {
- /* Protected mode: #GP(0)/#SS(0) if the segment is unusable.
- */
- exn = (s.unusable != 0);
- /* Protected mode: #GP(0)/#SS(0) if the memory
- * operand is outside the segment limit.
- */
- exn = exn || (off + sizeof(u64) > s.limit);
- }
- if (exn) {
- kvm_queue_exception_e(vcpu,
- seg_reg == VCPU_SREG_SS ?
- SS_VECTOR : GP_VECTOR,
- 0);
- return 1;
- }
-
+ if (is_protmode(vcpu))
+ return vmx_protmode_seg_check(vcpu, seg_reg, &s,
+ wr, sizeof(u64), off);
return 0;
}
--
2.1.4
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