* [PATCH v2 1/4] KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt
2022-02-02 9:50 [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Vitaly Kuznetsov
@ 2022-02-02 9:50 ` Vitaly Kuznetsov
2022-02-02 9:50 ` [PATCH v2 2/4] KVM: x86: Make kvm_hv_hypercall_enabled() static inline Vitaly Kuznetsov
` (3 subsequent siblings)
4 siblings, 0 replies; 8+ messages in thread
From: Vitaly Kuznetsov @ 2022-02-02 9:50 UTC (permalink / raw)
To: kvm, Paolo Bonzini
Cc: Sean Christopherson, Wanpeng Li, Jim Mattson, Maxim Levitsky,
Vineeth Pillai, linux-kernel
Similar to nVMX commit ed2a4800ae9d ("KVM: nVMX: Track whether changes in
L0 require MSR bitmap for L2 to be rebuilt"), introduce a flag to keep
track of whether MSR bitmap for L2 needs to be rebuilt due to changes in
MSR bitmap for L1 or switching to a different L2.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/svm/nested.c | 6 ++++++
arch/x86/kvm/svm/svm.c | 3 ++-
arch/x86/kvm/svm/svm.h | 9 +++++++++
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index cf206855ebf0..f27323728be2 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -193,6 +193,8 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
svm->nested.msrpm[p] = svm->msrpm[p] | value;
}
+ svm->nested.force_msr_bitmap_recalc = false;
+
svm->vmcb->control.msrpm_base_pa = __sme_set(__pa(svm->nested.msrpm));
return true;
@@ -494,6 +496,7 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12
if (svm->nested.vmcb12_gpa != svm->nested.last_vmcb12_gpa) {
new_vmcb12 = true;
svm->nested.last_vmcb12_gpa = svm->nested.vmcb12_gpa;
+ svm->nested.force_msr_bitmap_recalc = true;
}
if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_SEG))) {
@@ -1494,6 +1497,9 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
svm_switch_vmcb(svm, &svm->nested.vmcb02);
nested_vmcb02_prepare_control(svm);
+
+ svm->nested.force_msr_bitmap_recalc = true;
+
kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);
ret = 0;
out_free:
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 2c99b18d76c0..6b5e2ebcf5d4 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -664,6 +664,7 @@ static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr)
static void set_msr_interception_bitmap(struct kvm_vcpu *vcpu, u32 *msrpm,
u32 msr, int read, int write)
{
+ struct vcpu_svm *svm = to_svm(vcpu);
u8 bit_read, bit_write;
unsigned long tmp;
u32 offset;
@@ -694,7 +695,7 @@ static void set_msr_interception_bitmap(struct kvm_vcpu *vcpu, u32 *msrpm,
msrpm[offset] = tmp;
svm_hv_vmcb_dirty_nested_enlightenments(vcpu);
-
+ svm->nested.force_msr_bitmap_recalc = true;
}
void set_msr_interception(struct kvm_vcpu *vcpu, u32 *msrpm, u32 msr,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 47ef8f4a9358..92fc4f554634 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -163,6 +163,15 @@ struct svm_nested_state {
struct vmcb_save_area_cached save;
bool initialized;
+
+ /*
+ * Indicates whether MSR bitmap for L2 needs to be rebuilt due to
+ * changes in MSR bitmap for L1 or switching to a different L2. Note,
+ * this flag can only be used reliably in conjunction with a paravirt L1
+ * which informs L0 whether any changes to MSR bitmap for L2 were done
+ * on its side.
+ */
+ bool force_msr_bitmap_recalc;
};
struct vcpu_sev_es_state {
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v2 2/4] KVM: x86: Make kvm_hv_hypercall_enabled() static inline
2022-02-02 9:50 [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Vitaly Kuznetsov
2022-02-02 9:50 ` [PATCH v2 1/4] KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt Vitaly Kuznetsov
@ 2022-02-02 9:50 ` Vitaly Kuznetsov
2022-02-02 9:50 ` [PATCH v2 3/4] KVM: nSVM: Split off common definitions for Hyper-V on KVM and KVM on Hyper-V Vitaly Kuznetsov
` (2 subsequent siblings)
4 siblings, 0 replies; 8+ messages in thread
From: Vitaly Kuznetsov @ 2022-02-02 9:50 UTC (permalink / raw)
To: kvm, Paolo Bonzini
Cc: Sean Christopherson, Wanpeng Li, Jim Mattson, Maxim Levitsky,
Vineeth Pillai, linux-kernel
In preparation for using kvm_hv_hypercall_enabled() from SVM code, make
it static inline to avoid the need to export it. The function is a
simple check with only two call sites currently.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/hyperv.c | 5 -----
arch/x86/kvm/hyperv.h | 6 +++++-
2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 6e38a7d22e97..ec01ec9992d4 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2017,11 +2017,6 @@ int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
return ret;
}
-bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.hyperv_enabled && to_kvm_hv(vcpu->kvm)->hv_guest_os_id;
-}
-
static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
{
bool longmode;
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index ed1c4e546d04..e19c00ee9ab3 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -89,7 +89,11 @@ static inline u32 kvm_hv_get_vpindex(struct kvm_vcpu *vcpu)
int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host);
int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host);
-bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu);
+static inline bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.hyperv_enabled && to_kvm_hv(vcpu->kvm)->hv_guest_os_id;
+}
+
int kvm_hv_hypercall(struct kvm_vcpu *vcpu);
void kvm_hv_irq_routing_update(struct kvm *kvm);
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v2 3/4] KVM: nSVM: Split off common definitions for Hyper-V on KVM and KVM on Hyper-V
2022-02-02 9:50 [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Vitaly Kuznetsov
2022-02-02 9:50 ` [PATCH v2 1/4] KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt Vitaly Kuznetsov
2022-02-02 9:50 ` [PATCH v2 2/4] KVM: x86: Make kvm_hv_hypercall_enabled() static inline Vitaly Kuznetsov
@ 2022-02-02 9:50 ` Vitaly Kuznetsov
2022-02-02 9:51 ` [PATCH v2 4/4] KVM: nSVM: Implement Enlightened MSR-Bitmap feature Vitaly Kuznetsov
2022-02-02 17:14 ` [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Paolo Bonzini
4 siblings, 0 replies; 8+ messages in thread
From: Vitaly Kuznetsov @ 2022-02-02 9:50 UTC (permalink / raw)
To: kvm, Paolo Bonzini
Cc: Sean Christopherson, Wanpeng Li, Jim Mattson, Maxim Levitsky,
Vineeth Pillai, linux-kernel
In preparation to implementing Enlightened MSR-Bitmap feature for Hyper-V
on KVM, split off the required definitions into common 'svm/hyperv.h'
header.
No functional change intended.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/svm/hyperv.h | 35 +++++++++++++++++++++++++++++++++
arch/x86/kvm/svm/svm_onhyperv.h | 25 +----------------------
2 files changed, 36 insertions(+), 24 deletions(-)
create mode 100644 arch/x86/kvm/svm/hyperv.h
diff --git a/arch/x86/kvm/svm/hyperv.h b/arch/x86/kvm/svm/hyperv.h
new file mode 100644
index 000000000000..7d6d97968fb9
--- /dev/null
+++ b/arch/x86/kvm/svm/hyperv.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Common Hyper-V on KVM and KVM on Hyper-V definitions (SVM).
+ */
+
+#ifndef __ARCH_X86_KVM_SVM_HYPERV_H__
+#define __ARCH_X86_KVM_SVM_HYPERV_H__
+
+#include <asm/mshyperv.h>
+
+#include "../hyperv.h"
+
+/*
+ * Hyper-V uses the software reserved 32 bytes in VMCB
+ * control area to expose SVM enlightenments to guests.
+ */
+struct hv_enlightenments {
+ struct __packed hv_enlightenments_control {
+ u32 nested_flush_hypercall:1;
+ u32 msr_bitmap:1;
+ u32 enlightened_npt_tlb: 1;
+ u32 reserved:29;
+ } __packed hv_enlightenments_control;
+ u32 hv_vp_id;
+ u64 hv_vm_id;
+ u64 partition_assist_page;
+ u64 reserved;
+} __packed;
+
+/*
+ * Hyper-V uses the software reserved clean bit in VMCB
+ */
+#define VMCB_HV_NESTED_ENLIGHTENMENTS VMCB_SW
+
+#endif /* __ARCH_X86_KVM_SVM_HYPERV_H__ */
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index c53b8bf8d013..c787c032f68d 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -7,35 +7,12 @@
#define __ARCH_X86_KVM_SVM_ONHYPERV_H__
#if IS_ENABLED(CONFIG_HYPERV)
-#include <asm/mshyperv.h>
-#include "hyperv.h"
#include "kvm_onhyperv.h"
+#include "svm/hyperv.h"
static struct kvm_x86_ops svm_x86_ops;
-/*
- * Hyper-V uses the software reserved 32 bytes in VMCB
- * control area to expose SVM enlightenments to guests.
- */
-struct hv_enlightenments {
- struct __packed hv_enlightenments_control {
- u32 nested_flush_hypercall:1;
- u32 msr_bitmap:1;
- u32 enlightened_npt_tlb: 1;
- u32 reserved:29;
- } __packed hv_enlightenments_control;
- u32 hv_vp_id;
- u64 hv_vm_id;
- u64 partition_assist_page;
- u64 reserved;
-} __packed;
-
-/*
- * Hyper-V uses the software reserved clean bit in VMCB
- */
-#define VMCB_HV_NESTED_ENLIGHTENMENTS VMCB_SW
-
int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu);
static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v2 4/4] KVM: nSVM: Implement Enlightened MSR-Bitmap feature
2022-02-02 9:50 [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Vitaly Kuznetsov
` (2 preceding siblings ...)
2022-02-02 9:50 ` [PATCH v2 3/4] KVM: nSVM: Split off common definitions for Hyper-V on KVM and KVM on Hyper-V Vitaly Kuznetsov
@ 2022-02-02 9:51 ` Vitaly Kuznetsov
2022-02-02 17:14 ` [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Paolo Bonzini
4 siblings, 0 replies; 8+ messages in thread
From: Vitaly Kuznetsov @ 2022-02-02 9:51 UTC (permalink / raw)
To: kvm, Paolo Bonzini
Cc: Sean Christopherson, Wanpeng Li, Jim Mattson, Maxim Levitsky,
Vineeth Pillai, linux-kernel
Similar to nVMX commit 502d2bf5f2fd ("KVM: nVMX: Implement Enlightened MSR
Bitmap feature"), add support for the feature for nSVM (Hyper-V on KVM).
Notable differences from nVMX implementation:
- As the feature uses SW reserved fields in VMCB control, KVM needs to
make sure it's dealing with a Hyper-V guest (kvm_hv_hypercall_enabled()).
- 'msrpm_base_pa' needs to be always be overwritten in
nested_svm_vmrun_msrpm(), even when the update is skipped. As an
optimization, nested_vmcb02_prepare_control() copies it from VMCB01
so when MSR-Bitmap feature for L2 is disabled nothing needs to be done.
- 'struct vmcb_ctrl_area_cached' needs to be extended with clean
fields/sw reserved data and __nested_copy_vmcb_control_to_cache() needs to
copy it so nested_svm_vmrun_msrpm() can use it later.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/hyperv.c | 7 +------
arch/x86/kvm/svm/nested.c | 41 ++++++++++++++++++++++++++++++++-------
arch/x86/kvm/svm/svm.h | 2 ++
3 files changed, 37 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index ec01ec9992d4..9192b706be58 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2412,10 +2412,6 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
if (kvm_x86_ops.nested_ops->get_evmcs_version)
evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
- /* Skip NESTED_FEATURES if eVMCS is not supported */
- if (!evmcs_ver)
- --nent;
-
if (cpuid->nent < nent)
return -E2BIG;
@@ -2515,8 +2511,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
case HYPERV_CPUID_NESTED_FEATURES:
ent->eax = evmcs_ver;
- if (evmcs_ver)
- ent->eax |= HV_X64_NESTED_MSR_BITMAP;
+ ent->eax |= HV_X64_NESTED_MSR_BITMAP;
break;
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index f27323728be2..7b26a4b518f7 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -28,6 +28,7 @@
#include "cpuid.h"
#include "lapic.h"
#include "svm.h"
+#include "hyperv.h"
#define CC KVM_NESTED_VMENTER_CONSISTENCY_CHECK
@@ -165,14 +166,30 @@ void recalc_intercepts(struct vcpu_svm *svm)
vmcb_set_intercept(c, INTERCEPT_VMSAVE);
}
+/*
+ * Merge L0's (KVM) and L1's (Nested VMCB) MSR permission bitmaps. The function
+ * is optimized in that it only merges the parts where KVM MSR permission bitmap
+ * may contain zero bits.
+ */
static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
{
+ struct hv_enlightenments *hve =
+ (struct hv_enlightenments *)svm->nested.ctl.reserved_sw;
+ int i;
+
/*
- * This function merges the msr permission bitmaps of kvm and the
- * nested vmcb. It is optimized in that it only merges the parts where
- * the kvm msr permission bitmap may contain zero bits
+ * MSR bitmap update can be skipped when:
+ * - MSR bitmap for L1 hasn't changed.
+ * - Nested hypervisor (L1) is attempting to launch the same L2 as
+ * before.
+ * - Nested hypervisor (L1) is using Hyper-V emulation interface and
+ * tells KVM (L0) there were no changes in MSR bitmap for L2.
*/
- int i;
+ if (!svm->nested.force_msr_bitmap_recalc &&
+ kvm_hv_hypercall_enabled(&svm->vcpu) &&
+ hve->hv_enlightenments_control.msr_bitmap &&
+ (svm->nested.ctl.clean & VMCB_HV_NESTED_ENLIGHTENMENTS))
+ goto set_msrpm_base_pa;
if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
return true;
@@ -195,6 +212,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
svm->nested.force_msr_bitmap_recalc = false;
+set_msrpm_base_pa:
svm->vmcb->control.msrpm_base_pa = __sme_set(__pa(svm->nested.msrpm));
return true;
@@ -300,7 +318,8 @@ static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu)
}
static
-void __nested_copy_vmcb_control_to_cache(struct vmcb_ctrl_area_cached *to,
+void __nested_copy_vmcb_control_to_cache(struct kvm_vcpu *vcpu,
+ struct vmcb_ctrl_area_cached *to,
struct vmcb_control_area *from)
{
unsigned int i;
@@ -333,12 +352,19 @@ void __nested_copy_vmcb_control_to_cache(struct vmcb_ctrl_area_cached *to,
to->asid = from->asid;
to->msrpm_base_pa &= ~0x0fffULL;
to->iopm_base_pa &= ~0x0fffULL;
+
+ /* Hyper-V extensions (Enlightened VMCB) */
+ if (kvm_hv_hypercall_enabled(vcpu)) {
+ to->clean = from->clean;
+ memcpy(to->reserved_sw, from->reserved_sw,
+ sizeof(struct hv_enlightenments));
+ }
}
void nested_copy_vmcb_control_to_cache(struct vcpu_svm *svm,
struct vmcb_control_area *control)
{
- __nested_copy_vmcb_control_to_cache(&svm->nested.ctl, control);
+ __nested_copy_vmcb_control_to_cache(&svm->vcpu, &svm->nested.ctl, control);
}
static void __nested_copy_vmcb_save_to_cache(struct vmcb_save_area_cached *to,
@@ -1305,6 +1331,7 @@ static void nested_copy_vmcb_cache_to_control(struct vmcb_control_area *dst,
dst->virt_ext = from->virt_ext;
dst->pause_filter_count = from->pause_filter_count;
dst->pause_filter_thresh = from->pause_filter_thresh;
+ /* 'clean' and 'reserved_sw' are not changed by KVM */
}
static int svm_get_nested_state(struct kvm_vcpu *vcpu,
@@ -1437,7 +1464,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
goto out_free;
ret = -EINVAL;
- __nested_copy_vmcb_control_to_cache(&ctl_cached, ctl);
+ __nested_copy_vmcb_control_to_cache(vcpu, &ctl_cached, ctl);
if (!__nested_vmcb_check_controls(vcpu, &ctl_cached))
goto out_free;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 92fc4f554634..96473ecb2c6e 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -137,6 +137,8 @@ struct vmcb_ctrl_area_cached {
u32 event_inj_err;
u64 nested_cr3;
u64 virt_ext;
+ u32 clean;
+ u8 reserved_sw[32];
};
struct svm_nested_state {
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM
2022-02-02 9:50 [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Vitaly Kuznetsov
` (3 preceding siblings ...)
2022-02-02 9:51 ` [PATCH v2 4/4] KVM: nSVM: Implement Enlightened MSR-Bitmap feature Vitaly Kuznetsov
@ 2022-02-02 17:14 ` Paolo Bonzini
2022-02-03 9:51 ` Vitaly Kuznetsov
4 siblings, 1 reply; 8+ messages in thread
From: Paolo Bonzini @ 2022-02-02 17:14 UTC (permalink / raw)
To: Vitaly Kuznetsov, kvm
Cc: Sean Christopherson, Wanpeng Li, Jim Mattson, Maxim Levitsky,
Vineeth Pillai, linux-kernel
On 2/2/22 10:50, Vitaly Kuznetsov wrote:
> Changes since v1:
> - Patches 1/2 from "[PATCH 0/5] KVM: SVM: nSVM: Implement Enlightened
> MSR-Bitmap for Hyper-V-on-KVM and fix it for KVM-on-Hyper-V" are already
> merged, dropped.
> - Fix build when !CONFIG_HYPERV (PATCH3 "KVM: nSVM: Split off common
> definitions for Hyper-V on KVM and KVM on Hyper-V" added).
>
> Description:
>
> Enlightened MSR-Bitmap feature implements a PV protocol for L0 and L1
> hypervisors to collaborate and skip unneeded updates to MSR-Bitmap.
> KVM already implements the feature for KVM-on-Hyper-V.
>
> Vitaly Kuznetsov (4):
> KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be
> rebuilt
> KVM: x86: Make kvm_hv_hypercall_enabled() static inline
> KVM: nSVM: Split off common definitions for Hyper-V on KVM and KVM on
> Hyper-V
> KVM: nSVM: Implement Enlightened MSR-Bitmap feature
>
> arch/x86/kvm/hyperv.c | 12 +--------
> arch/x86/kvm/hyperv.h | 6 ++++-
> arch/x86/kvm/svm/hyperv.h | 35 ++++++++++++++++++++++++
> arch/x86/kvm/svm/nested.c | 47 ++++++++++++++++++++++++++++-----
> arch/x86/kvm/svm/svm.c | 3 ++-
> arch/x86/kvm/svm/svm.h | 11 ++++++++
> arch/x86/kvm/svm/svm_onhyperv.h | 25 +-----------------
> 7 files changed, 95 insertions(+), 44 deletions(-)
> create mode 100644 arch/x86/kvm/svm/hyperv.h
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM
2022-02-02 17:14 ` [PATCH v2 0/4] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM Paolo Bonzini
@ 2022-02-03 9:51 ` Vitaly Kuznetsov
2022-02-03 10:39 ` Paolo Bonzini
0 siblings, 1 reply; 8+ messages in thread
From: Vitaly Kuznetsov @ 2022-02-03 9:51 UTC (permalink / raw)
To: Paolo Bonzini
Cc: kvm, Sean Christopherson, Wanpeng Li, Jim Mattson, Maxim Levitsky,
Vineeth Pillai, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 542 bytes --]
Paolo Bonzini <pbonzini@redhat.com> writes:
> On 2/2/22 10:50, Vitaly Kuznetsov wrote:
...
>> KVM: nSVM: Implement Enlightened MSR-Bitmap feature
...
>
> Queued, thanks.
While writing a selftest for the feature, I've discovered an embarassing
bug: in nested_svm_vmrun_msrpm() I check bit number instead of bit
mask. It worked in testing by pure luck, it seems genuine Hyper-V sets
some other clean fields simultaneously.
Would it be possible to squash the attached patch in? Thanks!
I'll be sending out selftests shortly.
--
Vitaly
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From cfb538876ccc59dade7cadde553863bea8312f90 Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Thu, 3 Feb 2022 10:22:30 +0100
Subject: [PATCH] KVM: nSVM: Fix the check for VMCB_HV_NESTED_ENLIGHTENMENTS
bin in nested_svm_vmrun_msrpm()
VMCB_HV_NESTED_ENLIGHTENMENTS (VMCB_SW) is a bit number, not a bit mask.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/svm/nested.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 7b26a4b518f7..7acf4f2aa445 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -188,7 +188,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
if (!svm->nested.force_msr_bitmap_recalc &&
kvm_hv_hypercall_enabled(&svm->vcpu) &&
hve->hv_enlightenments_control.msr_bitmap &&
- (svm->nested.ctl.clean & VMCB_HV_NESTED_ENLIGHTENMENTS))
+ (svm->nested.ctl.clean & BIT(VMCB_HV_NESTED_ENLIGHTENMENTS)))
goto set_msrpm_base_pa;
if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
--
2.34.1
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