Allow VMWRITE in L1 to modify VM-exit information fields and report
this feature in L1's IA32_VMX_MISC MSR.
Note that this feature is a prerequisite for kvm in L1 to use VMCS
shadowing, once that feature is available.
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 105 ++++++++++++++++++++---------------------------------
1 file changed, 39 insertions(+), 66 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b4cfdcfdc1c1..72f295510f76 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -674,7 +674,7 @@ static struct pi_desc *vcpu_to_pi_desc(struct kvm_vcpu *vcpu)
[number##_HIGH] = VMCS12_OFFSET(name)+4
-static unsigned long shadow_read_only_fields[] = {
+static unsigned long shadow_fields[] = {
/*
* We do NOT shadow fields that are modified when L0
* traps and emulates any vmx instruction (e.g. VMPTRLD,
@@ -695,12 +695,7 @@ static unsigned long shadow_read_only_fields[] = {
VM_EXIT_INTR_ERROR_CODE,
EXIT_QUALIFICATION,
GUEST_LINEAR_ADDRESS,
- GUEST_PHYSICAL_ADDRESS
-};
-static int max_shadow_read_only_fields =
- ARRAY_SIZE(shadow_read_only_fields);
-
-static unsigned long shadow_read_write_fields[] = {
+ GUEST_PHYSICAL_ADDRESS,
TPR_THRESHOLD,
GUEST_RIP,
GUEST_RSP,
@@ -728,10 +723,9 @@ static unsigned long shadow_read_write_fields[] = {
HOST_FS_BASE,
HOST_GS_BASE,
HOST_FS_SELECTOR,
- HOST_GS_SELECTOR
+ HOST_GS_SELECTOR,
};
-static int max_shadow_read_write_fields =
- ARRAY_SIZE(shadow_read_write_fields);
+static int max_shadow_fields = ARRAY_SIZE(shadow_fields);
static const unsigned short vmcs_field_to_offset_table[] = {
FIELD(VIRTUAL_PROCESSOR_ID, virtual_processor_id),
@@ -2803,6 +2797,13 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
VMX_MISC_ACTIVITY_HLT;
vmx->nested.nested_vmx_misc_high = 0;
+ /*
+ * We can emulate "VMWRITE to any supported field," even if
+ * the hardware doesn't support it.
+ */
+ vmx->nested.nested_vmx_misc_low |=
+ MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS;
+
/*
* This MSR reports some information about VMX support. We
* should return information about the VMX we emulate for the
@@ -3765,10 +3766,8 @@ static void init_vmcs_shadow_fields(void)
{
int i, j;
- /* No checks for read only fields yet */
-
- for (i = j = 0; i < max_shadow_read_write_fields; i++) {
- switch (shadow_read_write_fields[i]) {
+ for (i = j = 0; i < max_shadow_fields; i++) {
+ switch (shadow_fields[i]) {
case GUEST_BNDCFGS:
if (!kvm_mpx_supported())
continue;
@@ -3778,22 +3777,16 @@ static void init_vmcs_shadow_fields(void)
}
if (j < i)
- shadow_read_write_fields[j] =
- shadow_read_write_fields[i];
+ shadow_fields[j] = shadow_fields[i];
j++;
}
- max_shadow_read_write_fields = j;
+ max_shadow_fields = j;
/* shadowed fields guest access without vmexit */
- for (i = 0; i < max_shadow_read_write_fields; i++) {
- clear_bit(shadow_read_write_fields[i],
- vmx_vmwrite_bitmap);
- clear_bit(shadow_read_write_fields[i],
- vmx_vmread_bitmap);
+ for (i = 0; i < max_shadow_fields; i++) {
+ clear_bit(shadow_fields[i], vmx_vmwrite_bitmap);
+ clear_bit(shadow_fields[i], vmx_vmread_bitmap);
}
- for (i = 0; i < max_shadow_read_only_fields; i++)
- clear_bit(shadow_read_only_fields[i],
- vmx_vmread_bitmap);
}
static __init int alloc_kvm_area(void)
@@ -7294,14 +7287,13 @@ static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
unsigned long field;
u64 field_value;
struct vmcs *shadow_vmcs = vmx->vmcs01.shadow_vmcs;
- const unsigned long *fields = shadow_read_write_fields;
- const int num_fields = max_shadow_read_write_fields;
+ unsigned long *fields = shadow_fields;
preempt_disable();
vmcs_load(shadow_vmcs);
- for (i = 0; i < num_fields; i++) {
+ for (i = 0; i < max_shadow_fields; i++) {
field = fields[i];
switch (vmcs_field_type(field)) {
case VMCS_FIELD_TYPE_U16:
@@ -7331,43 +7323,31 @@ static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
{
- const unsigned long *fields[] = {
- shadow_read_write_fields,
- shadow_read_only_fields
- };
- const int max_fields[] = {
- max_shadow_read_write_fields,
- max_shadow_read_only_fields
- };
- int i, q;
+ int i;
unsigned long field;
u64 field_value = 0;
struct vmcs *shadow_vmcs = vmx->vmcs01.shadow_vmcs;
+ unsigned long *fields = shadow_fields;
vmcs_load(shadow_vmcs);
- for (q = 0; q < ARRAY_SIZE(fields); q++) {
- for (i = 0; i < max_fields[q]; i++) {
- field = fields[q][i];
- vmcs12_read_any(&vmx->vcpu, field, &field_value);
-
- switch (vmcs_field_type(field)) {
- case VMCS_FIELD_TYPE_U16:
- vmcs_write16(field, (u16)field_value);
- break;
- case VMCS_FIELD_TYPE_U32:
- vmcs_write32(field, (u32)field_value);
- break;
- case VMCS_FIELD_TYPE_U64:
- vmcs_write64(field, (u64)field_value);
- break;
- case VMCS_FIELD_TYPE_NATURAL_WIDTH:
- vmcs_writel(field, (long)field_value);
- break;
- default:
- WARN_ON(1);
- break;
- }
+ for (i = 0; i < max_shadow_fields; i++) {
+ field = fields[i];
+ vmcs12_read_any(&vmx->vcpu, field, &field_value);
+
+ switch (vmcs_field_type(field)) {
+ case VMCS_FIELD_TYPE_U16:
+ vmcs_write16(field, (u16)field_value);
+ break;
+ case VMCS_FIELD_TYPE_U32:
+ vmcs_write32(field, (u32)field_value);
+ break;
+ case VMCS_FIELD_TYPE_U64:
+ vmcs_write64(field, (u64)field_value);
+ break;
+ case VMCS_FIELD_TYPE_NATURAL_WIDTH:
+ vmcs_writel(field, (long)field_value);
+ break;
}
}
@@ -7467,14 +7447,7 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
}
}
-
field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
- if (vmcs_field_readonly(field)) {
- nested_vmx_failValid(vcpu,
- VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT);
- return kvm_skip_emulated_instruction(vcpu);
- }
-
if (vmcs12_write_any(vcpu, field, field_value) < 0) {
nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
return kvm_skip_emulated_instruction(vcpu);
--
2.13.2.725.g09c95d1e9-goog
