[PATCH 11/14] KVM: nVMX: hyper-v: Introduce nested_vmx_evmptr12() and nested_vmx_is_evmptr12_valid() helpers

From: Vitaly Kuznetsov
Date: Wed Oct 25 2023 - 11:25:59 EST


'vmx->nested.hv_evmcs_vmptr' accesses are all over the place so hiding
'hv_evmcs_vmptr' under 'ifdef CONFIG_KVM_HYPERV' would take a lot of
ifdefs. Introduce 'nested_vmx_evmptr12()' accessor and
'nested_vmx_is_evmptr12_valid()' checker instead. Note, several explicit

nested_vmx_evmptr12(vmx) != EVMPTR_INVALID

comparisons exist for a reson: 'nested_vmx_is_evmptr12_valid()' also checks
against 'EVMPTR_MAP_PENDING' and in these places this is undesireable. It
is possible to e.g. introduce 'nested_vmx_is_evmptr12_invalid()' and turn
these sites into

!nested_vmx_is_evmptr12_invalid(vmx)

eliminating the need for 'nested_vmx_evmptr12()' but this seems to create
even more confusion.

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/kvm/vmx/hyperv.h | 10 +++++++++
arch/x86/kvm/vmx/nested.c | 44 +++++++++++++++++++--------------------
arch/x86/kvm/vmx/nested.h | 2 +-
3 files changed, 33 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kvm/vmx/hyperv.h b/arch/x86/kvm/vmx/hyperv.h
index 933ef6cad5e6..ba1a95ea72b7 100644
--- a/arch/x86/kvm/vmx/hyperv.h
+++ b/arch/x86/kvm/vmx/hyperv.h
@@ -4,6 +4,7 @@

#include <linux/kvm_host.h>
#include "vmcs12.h"
+#include "vmx.h"

#define EVMPTR_INVALID (-1ULL)
#define EVMPTR_MAP_PENDING (-2ULL)
@@ -20,7 +21,14 @@ enum nested_evmptrld_status {
EVMPTRLD_ERROR,
};

+struct vcpu_vmx;
+
#ifdef CONFIG_KVM_HYPERV
+static inline gpa_t nested_vmx_evmptr12(struct vcpu_vmx *vmx) { return vmx->nested.hv_evmcs_vmptr; }
+static inline bool nested_vmx_is_evmptr12_valid(struct vcpu_vmx *vmx)
+{
+ return evmptr_is_valid(vmx->nested.hv_evmcs_vmptr);
+}
u64 nested_get_evmptr(struct kvm_vcpu *vcpu);
uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu);
int nested_enable_evmcs(struct kvm_vcpu *vcpu,
@@ -30,6 +38,8 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12);
bool nested_evmcs_l2_tlb_flush_enabled(struct kvm_vcpu *vcpu);
void vmx_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu);
#else
+static inline gpa_t nested_vmx_evmptr12(struct vcpu_vmx *vmx) { return EVMPTR_INVALID; }
+static inline bool nested_vmx_is_evmptr12_valid(struct vcpu_vmx *vmx) { return false; }
static inline u64 nested_get_evmptr(struct kvm_vcpu *vcpu) { return EVMPTR_INVALID; }
static inline void nested_evmcs_filter_control_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) {}
static inline bool nested_evmcs_l2_tlb_flush_enabled(struct kvm_vcpu *vcpu) { return false; }
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index d0d735974b2c..b45586588bae 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -179,7 +179,7 @@ static int nested_vmx_failValid(struct kvm_vcpu *vcpu,
* VM_INSTRUCTION_ERROR is not shadowed. Enlightened VMCS 'shadows' all
* fields and thus must be synced.
*/
- if (to_vmx(vcpu)->nested.hv_evmcs_vmptr != EVMPTR_INVALID)
+ if (nested_vmx_evmptr12(to_vmx(vcpu)) != EVMPTR_INVALID)
to_vmx(vcpu)->nested.need_vmcs12_to_shadow_sync = true;

return kvm_skip_emulated_instruction(vcpu);
@@ -194,7 +194,7 @@ static int nested_vmx_fail(struct kvm_vcpu *vcpu, u32 vm_instruction_error)
* can't be done if there isn't a current VMCS.
*/
if (vmx->nested.current_vmptr == INVALID_GPA &&
- !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ !nested_vmx_is_evmptr12_valid(vmx))
return nested_vmx_failInvalid(vcpu);

return nested_vmx_failValid(vcpu, vm_instruction_error);
@@ -230,7 +230,7 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
struct vcpu_vmx *vmx = to_vmx(vcpu);

- if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+ if (nested_vmx_is_evmptr12_valid(vmx)) {
kvm_vcpu_unmap(vcpu, &vmx->nested.hv_evmcs_map, true);
vmx->nested.hv_evmcs = NULL;
}
@@ -2011,7 +2011,7 @@ static enum nested_evmptrld_status nested_vmx_handle_enlightened_vmptrld(
return EVMPTRLD_DISABLED;
}

- if (unlikely(evmcs_gpa != vmx->nested.hv_evmcs_vmptr)) {
+ if (unlikely(evmcs_gpa != nested_vmx_evmptr12(vmx))) {
vmx->nested.current_vmptr = INVALID_GPA;

nested_release_evmcs(vcpu);
@@ -2089,7 +2089,7 @@ void nested_sync_vmcs12_to_shadow(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);

- if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ if (nested_vmx_is_evmptr12_valid(vmx))
copy_vmcs12_to_enlightened(vmx);
else
copy_vmcs12_to_shadow(vmx);
@@ -2243,7 +2243,7 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0
u32 exec_control;
u64 guest_efer = nested_vmx_calc_efer(vmx, vmcs12);

- if (vmx->nested.dirty_vmcs12 || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ if (vmx->nested.dirty_vmcs12 || nested_vmx_is_evmptr12_valid(vmx))
prepare_vmcs02_early_rare(vmx, vmcs12);

/*
@@ -2538,11 +2538,11 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
struct vcpu_vmx *vmx = to_vmx(vcpu);
bool load_guest_pdptrs_vmcs12 = false;

- if (vmx->nested.dirty_vmcs12 || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+ if (vmx->nested.dirty_vmcs12 || nested_vmx_is_evmptr12_valid(vmx)) {
prepare_vmcs02_rare(vmx, vmcs12);
vmx->nested.dirty_vmcs12 = false;

- load_guest_pdptrs_vmcs12 = !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr) ||
+ load_guest_pdptrs_vmcs12 = !nested_vmx_is_evmptr12_valid(vmx) ||
!(vmx->nested.hv_evmcs->hv_clean_fields &
HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1);
}
@@ -2665,7 +2665,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
* bits when it changes a field in eVMCS. Mark all fields as clean
* here.
*/
- if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ if (nested_vmx_is_evmptr12_valid(vmx))
vmx->nested.hv_evmcs->hv_clean_fields |=
HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;

@@ -3173,7 +3173,7 @@ static bool nested_get_evmcs_page(struct kvm_vcpu *vcpu)
* properly reflected.
*/
if (guest_cpuid_has_evmcs(vcpu) &&
- vmx->nested.hv_evmcs_vmptr == EVMPTR_MAP_PENDING) {
+ nested_vmx_evmptr12(vmx) == EVMPTR_MAP_PENDING) {
enum nested_evmptrld_status evmptrld_status =
nested_vmx_handle_enlightened_vmptrld(vcpu, false);

@@ -3543,7 +3543,7 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,

load_vmcs12_host_state(vcpu, vmcs12);
vmcs12->vm_exit_reason = exit_reason.full;
- if (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ if (enable_shadow_vmcs || nested_vmx_is_evmptr12_valid(vmx))
vmx->nested.need_vmcs12_to_shadow_sync = true;
return NVMX_VMENTRY_VMEXIT;
}
@@ -3576,7 +3576,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
if (CC(evmptrld_status == EVMPTRLD_VMFAIL))
return nested_vmx_failInvalid(vcpu);

- if (CC(!evmptr_is_valid(vmx->nested.hv_evmcs_vmptr) &&
+ if (CC(!nested_vmx_is_evmptr12_valid(vmx) &&
vmx->nested.current_vmptr == INVALID_GPA))
return nested_vmx_failInvalid(vcpu);

@@ -3591,7 +3591,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
if (CC(vmcs12->hdr.shadow_vmcs))
return nested_vmx_failInvalid(vcpu);

- if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+ if (nested_vmx_is_evmptr12_valid(vmx)) {
copy_enlightened_to_vmcs12(vmx, vmx->nested.hv_evmcs->hv_clean_fields);
/* Enlightened VMCS doesn't have launch state */
vmcs12->launch_state = !launch;
@@ -4336,11 +4336,11 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);

- if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ if (nested_vmx_is_evmptr12_valid(vmx))
sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12);

vmx->nested.need_sync_vmcs02_to_vmcs12_rare =
- !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr);
+ !nested_vmx_is_evmptr12_valid(vmx);

vmcs12->guest_cr0 = vmcs12_guest_cr0(vcpu, vmcs12);
vmcs12->guest_cr4 = vmcs12_guest_cr4(vcpu, vmcs12);
@@ -4861,7 +4861,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
}

if ((vm_exit_reason != -1) &&
- (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)))
+ (enable_shadow_vmcs || nested_vmx_is_evmptr12_valid(vmx)))
vmx->nested.need_vmcs12_to_shadow_sync = true;

/* in case we halted in L2 */
@@ -5327,7 +5327,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
vmptr + offsetof(struct vmcs12,
launch_state),
&zero, sizeof(zero));
- } else if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) {
+ } else if (vmx->nested.hv_evmcs && vmptr == nested_vmx_evmptr12(vmx)) {
nested_release_evmcs(vcpu);
}

@@ -5367,7 +5367,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
/* Decode instruction info and find the field to read */
field = kvm_register_read(vcpu, (((instr_info) >> 28) & 0xf));

- if (!evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+ if (!nested_vmx_is_evmptr12_valid(vmx)) {
/*
* In VMX non-root operation, when the VMCS-link pointer is INVALID_GPA,
* any VMREAD sets the ALU flags for VMfailInvalid.
@@ -5593,7 +5593,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
return nested_vmx_fail(vcpu, VMXERR_VMPTRLD_VMXON_POINTER);

/* Forbid normal VMPTRLD if Enlightened version was used */
- if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ if (nested_vmx_is_evmptr12_valid(vmx))
return 1;

if (vmx->nested.current_vmptr != vmptr) {
@@ -5656,7 +5656,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu)
if (!nested_vmx_check_permission(vcpu))
return 1;

- if (unlikely(evmptr_is_valid(to_vmx(vcpu)->nested.hv_evmcs_vmptr)))
+ if (unlikely(nested_vmx_is_evmptr12_valid(to_vmx(vcpu))))
return 1;

if (get_vmx_mem_address(vcpu, exit_qual, instr_info,
@@ -6442,7 +6442,7 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
kvm_state.size += sizeof(user_vmx_nested_state->vmcs12);

/* 'hv_evmcs_vmptr' can also be EVMPTR_MAP_PENDING here */
- if (vmx->nested.hv_evmcs_vmptr != EVMPTR_INVALID)
+ if (nested_vmx_evmptr12(vmx) != EVMPTR_INVALID)
kvm_state.flags |= KVM_STATE_NESTED_EVMCS;

if (is_guest_mode(vcpu) &&
@@ -6498,7 +6498,7 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
} else {
copy_vmcs02_to_vmcs12_rare(vcpu, get_vmcs12(vcpu));
if (!vmx->nested.need_vmcs12_to_shadow_sync) {
- if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+ if (nested_vmx_is_evmptr12_valid(vmx))
/*
* L1 hypervisor is not obliged to keep eVMCS
* clean fields data always up-to-date while
diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index b0f2e26c1aea..0cedb80c5c94 100644
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -58,7 +58,7 @@ static inline int vmx_has_valid_vmcs12(struct kvm_vcpu *vcpu)

/* 'hv_evmcs_vmptr' can also be EVMPTR_MAP_PENDING here */
return vmx->nested.current_vmptr != -1ull ||
- vmx->nested.hv_evmcs_vmptr != EVMPTR_INVALID;
+ nested_vmx_evmptr12(vmx) != EVMPTR_INVALID;
}

static inline u16 nested_get_vpid02(struct kvm_vcpu *vcpu)
--
2.41.0