xen/arch/x86/hvm/Kconfig | 10 ++++++++++ xen/arch/x86/hvm/Makefile | 2 +- xen/arch/x86/hvm/hvm.c | 5 +++-- xen/arch/x86/hvm/viridian/viridian.c | 8 ++++---- xen/arch/x86/hvm/vlapic.c | 11 +++++++---- xen/arch/x86/include/asm/hvm/domain.h | 2 ++ xen/arch/x86/include/asm/hvm/hvm.h | 3 ++- xen/arch/x86/include/asm/hvm/vcpu.h | 2 ++ xen/arch/x86/include/asm/hvm/viridian.h | 15 +++++++++++++++ 9 files changed, 46 insertions(+), 12 deletions(-)
From: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
Add config option VIRIDIAN that covers viridian code within HVM.
Calls to viridian functions guarded by is_viridian_domain() and related macros.
Having this option may be beneficial by reducing code footprint for systems
that are not using Hyper-V.
[grygorii_strashko@epam.com: fixed NULL pointer deref in
viridian_save_domain_ctxt(); stub viridian_vcpu/domain_init/deinit()]
Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
Signed-off-by: Grygorii Strashko <grygorii_strashko@epam.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
---
changes in v8:
- drop checks from viridian_load_vcpu/domain_ctxt()
- drop check "value != 0" in HVM_PARAM_VIRIDIAN handler, laways return
-ENODEV for VIRIDIAN=n
changes in v7:
- s/!is_viridian_vcpu()/!IS_ENABLED(CONFIG_VIRIDIAN) checks in
viridian_load_vcpu/domain_ctxt(), because it is not
guaranteed that HVM_PARAM_VIRIDIAN will be loaded before
viridian_load_vcpu_ctxt() is called (comment from Jason Andryuk)
changes in v6:
- add stubs for viridian_vcpu/domain_init/deinit()
- update Kconfig description
- make set(HVM_PARAM_VIRIDIAN) return -ENODEV
if (!IS_ENABLED(CONFIG_VIRIDIAN) && value)
changes in v5:
- drop "depends on AMD_SVM || INTEL_VMX"
- return -EILSEQ from viridian_load_x() if !VIRIDIAN
changes in v4:
- s/HVM_VIRIDIAN/VIRIDIAN
- add "depends on AMD_SVM || INTEL_VMX"
- add guard !is_viridian_vcpu() checks in viridian_load_vcpu_ctxt/viridian_load_domain_ctxt
changes in v3:
- fixed NULL pointer deref in viridian_save_domain_ctxt() reported for v2,
which caused v2 revert by commit 1fffcf10cd71 ("Revert "x86: make Viridian
support optional")
v7: https://patchwork.kernel.org/project/xen-devel/patch/20251031161716.1222956-1-grygorii_strashko@epam.com/
v6: https://patchwork.kernel.org/project/xen-devel/patch/20251023151807.560843-1-grygorii_strashko@epam.com/
v5: https://patchwork.kernel.org/project/xen-devel/patch/20250930125215.1087214-1-grygorii_strashko@epam.com/
v4: https://patchwork.kernel.org/project/xen-devel/patch/20250919163139.2821531-1-grygorii_strashko@epam.com/
v3: https://patchwork.kernel.org/project/xen-devel/patch/20250916134114.2214104-1-grygorii_strashko@epam.com/
v2: https://patchwork.kernel.org/project/xen-devel/patch/20250321092633.3982645-1-Sergiy_Kibrik@epam.com/
xen/arch/x86/hvm/Kconfig | 10 ++++++++++
xen/arch/x86/hvm/Makefile | 2 +-
xen/arch/x86/hvm/hvm.c | 5 +++--
xen/arch/x86/hvm/viridian/viridian.c | 8 ++++----
xen/arch/x86/hvm/vlapic.c | 11 +++++++----
xen/arch/x86/include/asm/hvm/domain.h | 2 ++
xen/arch/x86/include/asm/hvm/hvm.h | 3 ++-
xen/arch/x86/include/asm/hvm/vcpu.h | 2 ++
xen/arch/x86/include/asm/hvm/viridian.h | 15 +++++++++++++++
9 files changed, 46 insertions(+), 12 deletions(-)
diff --git a/xen/arch/x86/hvm/Kconfig b/xen/arch/x86/hvm/Kconfig
index 5e86cac26e1b..5c47a45c9350 100644
--- a/xen/arch/x86/hvm/Kconfig
+++ b/xen/arch/x86/hvm/Kconfig
@@ -75,6 +75,16 @@ config ALTP2M
If unsure, stay with defaults.
+config VIRIDIAN
+ bool "Hyper-V enlightenments for guests" if EXPERT
+ default y
+ help
+ Support optimizations for Hyper-V guests such as hypercalls, efficient
+ timers and interrupt handling. This is to improve performance and
+ compatibility of Windows VMs.
+
+ If unsure, say Y.
+
config MEM_PAGING
bool "Xen memory paging support (UNSUPPORTED)" if UNSUPPORTED
depends on VM_EVENT
diff --git a/xen/arch/x86/hvm/Makefile b/xen/arch/x86/hvm/Makefile
index 6ec2c8f2db56..736eb3f966e9 100644
--- a/xen/arch/x86/hvm/Makefile
+++ b/xen/arch/x86/hvm/Makefile
@@ -1,6 +1,6 @@
obj-$(CONFIG_AMD_SVM) += svm/
obj-$(CONFIG_INTEL_VMX) += vmx/
-obj-y += viridian/
+obj-$(CONFIG_VIRIDIAN) += viridian/
obj-y += asid.o
obj-y += dm.o
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 88ad4100001e..7299cfa90ad5 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4231,8 +4231,9 @@ static int hvm_set_param(struct domain *d, uint32_t index, uint64_t value)
rc = -EINVAL;
break;
case HVM_PARAM_VIRIDIAN:
- if ( (value & ~HVMPV_feature_mask) ||
- !(value & HVMPV_base_freq) )
+ if ( !IS_ENABLED(CONFIG_VIRIDIAN) )
+ rc = -ENODEV;
+ else if ( (value & ~HVMPV_feature_mask) || !(value & HVMPV_base_freq) )
rc = -EINVAL;
break;
case HVM_PARAM_IDENT_PT:
diff --git a/xen/arch/x86/hvm/viridian/viridian.c b/xen/arch/x86/hvm/viridian/viridian.c
index f79cffcb3767..90e749ceb581 100644
--- a/xen/arch/x86/hvm/viridian/viridian.c
+++ b/xen/arch/x86/hvm/viridian/viridian.c
@@ -1097,14 +1097,14 @@ static int cf_check viridian_save_domain_ctxt(
{
const struct domain *d = v->domain;
const struct viridian_domain *vd = d->arch.hvm.viridian;
- struct hvm_viridian_domain_context ctxt = {
- .hypercall_gpa = vd->hypercall_gpa.raw,
- .guest_os_id = vd->guest_os_id.raw,
- };
+ struct hvm_viridian_domain_context ctxt = {};
if ( !is_viridian_domain(d) )
return 0;
+ ctxt.hypercall_gpa = vd->hypercall_gpa.raw;
+ ctxt.guest_os_id = vd->guest_os_id.raw,
+
viridian_time_save_domain_ctxt(d, &ctxt);
viridian_synic_save_domain_ctxt(d, &ctxt);
diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 4121285daef8..b315e56d3f18 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -447,7 +447,8 @@ void vlapic_EOI_set(struct vlapic *vlapic)
* priority vector and then recurse to handle the lower priority
* vector.
*/
- bool missed_eoi = viridian_apic_assist_completed(v);
+ bool missed_eoi = has_viridian_apic_assist(v->domain) &&
+ viridian_apic_assist_completed(v);
int vector;
again:
@@ -463,7 +464,7 @@ void vlapic_EOI_set(struct vlapic *vlapic)
* NOTE: It is harmless to call viridian_apic_assist_clear() on a
* recursion, even though it is not necessary.
*/
- if ( !missed_eoi )
+ if ( has_viridian_apic_assist(v->domain) && !missed_eoi )
viridian_apic_assist_clear(v);
vlapic_clear_vector(vector, &vlapic->regs->data[APIC_ISR]);
@@ -1375,7 +1376,8 @@ int vlapic_has_pending_irq(struct vcpu *v)
* If so, we need to emulate the EOI here before comparing ISR
* with IRR.
*/
- if ( viridian_apic_assist_completed(v) )
+ if ( has_viridian_apic_assist(v->domain) &&
+ viridian_apic_assist_completed(v) )
vlapic_EOI_set(vlapic);
isr = vlapic_find_highest_isr(vlapic);
@@ -1388,7 +1390,8 @@ int vlapic_has_pending_irq(struct vcpu *v)
if ( isr >= 0 &&
(irr & 0xf0) <= (isr & 0xf0) )
{
- viridian_apic_assist_clear(v);
+ if ( has_viridian_apic_assist(v->domain) )
+ viridian_apic_assist_clear(v);
return -1;
}
diff --git a/xen/arch/x86/include/asm/hvm/domain.h b/xen/arch/x86/include/asm/hvm/domain.h
index 94d19730b2c1..83be2bd1c29c 100644
--- a/xen/arch/x86/include/asm/hvm/domain.h
+++ b/xen/arch/x86/include/asm/hvm/domain.h
@@ -105,7 +105,9 @@ struct hvm_domain {
/* hypervisor intercepted msix table */
struct list_head msixtbl_list;
+#ifdef CONFIG_VIRIDIAN
struct viridian_domain *viridian;
+#endif
/*
* TSC value that VCPUs use to calculate their tsc_offset value.
diff --git a/xen/arch/x86/include/asm/hvm/hvm.h b/xen/arch/x86/include/asm/hvm/hvm.h
index 927427764c9e..93da4dd2dc4b 100644
--- a/xen/arch/x86/include/asm/hvm/hvm.h
+++ b/xen/arch/x86/include/asm/hvm/hvm.h
@@ -514,7 +514,8 @@ hvm_get_cpl(struct vcpu *v)
(has_hvm_params(d) ? (d)->arch.hvm.params[HVM_PARAM_VIRIDIAN] : 0)
#define is_viridian_domain(d) \
- (is_hvm_domain(d) && (viridian_feature_mask(d) & HVMPV_base_freq))
+ (IS_ENABLED(CONFIG_VIRIDIAN) && \
+ is_hvm_domain(d) && (viridian_feature_mask(d) & HVMPV_base_freq))
#define is_viridian_vcpu(v) \
is_viridian_domain((v)->domain)
diff --git a/xen/arch/x86/include/asm/hvm/vcpu.h b/xen/arch/x86/include/asm/hvm/vcpu.h
index 3cf7a71fd309..eae9ac53767b 100644
--- a/xen/arch/x86/include/asm/hvm/vcpu.h
+++ b/xen/arch/x86/include/asm/hvm/vcpu.h
@@ -173,7 +173,9 @@ struct hvm_vcpu {
/* Pending hw/sw interrupt (.vector = -1 means nothing pending). */
struct x86_event inject_event;
+#ifdef CONFIG_VIRIDIAN
struct viridian_vcpu *viridian;
+#endif
};
#endif /* __ASM_X86_HVM_VCPU_H__ */
diff --git a/xen/arch/x86/include/asm/hvm/viridian.h b/xen/arch/x86/include/asm/hvm/viridian.h
index 47c9d13841ac..07ea95d4ae6e 100644
--- a/xen/arch/x86/include/asm/hvm/viridian.h
+++ b/xen/arch/x86/include/asm/hvm/viridian.h
@@ -86,11 +86,26 @@ viridian_hypercall(struct cpu_user_regs *regs);
void viridian_time_domain_freeze(const struct domain *d);
void viridian_time_domain_thaw(const struct domain *d);
+#if defined(CONFIG_VIRIDIAN)
int viridian_vcpu_init(struct vcpu *v);
int viridian_domain_init(struct domain *d);
void viridian_vcpu_deinit(struct vcpu *v);
void viridian_domain_deinit(struct domain *d);
+#else
+static inline int viridian_vcpu_init(struct vcpu *v)
+{
+ return 0;
+}
+
+static inline int viridian_domain_init(struct domain *d)
+{
+ return 0;
+}
+
+static inline void viridian_vcpu_deinit(struct vcpu *v) {}
+static inline void viridian_domain_deinit(struct domain *d) {}
+#endif
void viridian_apic_assist_set(const struct vcpu *v);
bool viridian_apic_assist_completed(const struct vcpu *v);
--
2.34.1(adding v8 tag to subject) On 19.11.2025 20:32, Grygorii Strashko wrote: > From: Sergiy Kibrik <Sergiy_Kibrik@epam.com> > > Add config option VIRIDIAN that covers viridian code within HVM. > Calls to viridian functions guarded by is_viridian_domain() and related macros. > Having this option may be beneficial by reducing code footprint for systems > that are not using Hyper-V. > > [grygorii_strashko@epam.com: fixed NULL pointer deref in > viridian_save_domain_ctxt(); stub viridian_vcpu/domain_init/deinit()] > Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com> > Signed-off-by: Grygorii Strashko <grygorii_strashko@epam.com> > Reviewed-by: Jason Andryuk <jason.andryuk@amd.com> As before - this R-b likely would need dropping, ... > --- > changes in v8: > - drop checks from viridian_load_vcpu/domain_ctxt() > - drop check "value != 0" in HVM_PARAM_VIRIDIAN handler, laways return > -ENODEV for VIRIDIAN=n ... when more than just cosmetic changes are made. Jason, please can you indicate whether it's fine to retain? > --- a/xen/arch/x86/hvm/Makefile > +++ b/xen/arch/x86/hvm/Makefile > @@ -1,6 +1,6 @@ > obj-$(CONFIG_AMD_SVM) += svm/ > obj-$(CONFIG_INTEL_VMX) += vmx/ > -obj-y += viridian/ > +obj-$(CONFIG_VIRIDIAN) += viridian/ When committing, I'll likely take the liberty to also move the altered line up, to restore proper alphabetical sorting here. > --- a/xen/arch/x86/include/asm/hvm/viridian.h > +++ b/xen/arch/x86/include/asm/hvm/viridian.h > @@ -86,11 +86,26 @@ viridian_hypercall(struct cpu_user_regs *regs); > void viridian_time_domain_freeze(const struct domain *d); > void viridian_time_domain_thaw(const struct domain *d); > > +#if defined(CONFIG_VIRIDIAN) Similarly I'm likely going to take the liberty and change this to #ifdef, just like you have it elsewhere. Preferably with the adjustments: Reviewed-by: Jan Beulich <jbeulich@suse.com> Jan
Hi Jan, On 20.11.25 10:50, Jan Beulich wrote: > (adding v8 tag to subject) > > On 19.11.2025 20:32, Grygorii Strashko wrote: >> From: Sergiy Kibrik <Sergiy_Kibrik@epam.com> >> >> Add config option VIRIDIAN that covers viridian code within HVM. >> Calls to viridian functions guarded by is_viridian_domain() and related macros. >> Having this option may be beneficial by reducing code footprint for systems >> that are not using Hyper-V. >> >> [grygorii_strashko@epam.com: fixed NULL pointer deref in >> viridian_save_domain_ctxt(); stub viridian_vcpu/domain_init/deinit()] >> Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com> >> Signed-off-by: Grygorii Strashko <grygorii_strashko@epam.com> >> Reviewed-by: Jason Andryuk <jason.andryuk@amd.com> > > As before - this R-b likely would need dropping, ... > >> --- >> changes in v8: >> - drop checks from viridian_load_vcpu/domain_ctxt() >> - drop check "value != 0" in HVM_PARAM_VIRIDIAN handler, laways return >> -ENODEV for VIRIDIAN=n > > ... when more than just cosmetic changes are made. Jason, please can you > indicate whether it's fine to retain? Sorry, I'll be more careful with tags. > >> --- a/xen/arch/x86/hvm/Makefile >> +++ b/xen/arch/x86/hvm/Makefile >> @@ -1,6 +1,6 @@ >> obj-$(CONFIG_AMD_SVM) += svm/ >> obj-$(CONFIG_INTEL_VMX) += vmx/ >> -obj-y += viridian/ >> +obj-$(CONFIG_VIRIDIAN) += viridian/ > > When committing, I'll likely take the liberty to also move the altered line > up, to restore proper alphabetical sorting here. > >> --- a/xen/arch/x86/include/asm/hvm/viridian.h >> +++ b/xen/arch/x86/include/asm/hvm/viridian.h >> @@ -86,11 +86,26 @@ viridian_hypercall(struct cpu_user_regs *regs); >> void viridian_time_domain_freeze(const struct domain *d); >> void viridian_time_domain_thaw(const struct domain *d); >> >> +#if defined(CONFIG_VIRIDIAN) > > Similarly I'm likely going to take the liberty and change this to #ifdef, > just like you have it elsewhere. I'm ok with mentioned adjustments. > > Preferably with the adjustments: > Reviewed-by: Jan Beulich <jbeulich@suse.com> Thank you. -- Best regards, -grygorii
On 2025-11-20 05:42, Grygorii Strashko wrote: > Hi Jan, > > On 20.11.25 10:50, Jan Beulich wrote: >> (adding v8 tag to subject) >> >> On 19.11.2025 20:32, Grygorii Strashko wrote: >>> From: Sergiy Kibrik <Sergiy_Kibrik@epam.com> >>> >>> Add config option VIRIDIAN that covers viridian code within HVM. >>> Calls to viridian functions guarded by is_viridian_domain() and >>> related macros. >>> Having this option may be beneficial by reducing code footprint for >>> systems >>> that are not using Hyper-V. >>> >>> [grygorii_strashko@epam.com: fixed NULL pointer deref in >>> viridian_save_domain_ctxt(); stub viridian_vcpu/domain_init/deinit()] >>> Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com> >>> Signed-off-by: Grygorii Strashko <grygorii_strashko@epam.com> >>> Reviewed-by: Jason Andryuk <jason.andryuk@amd.com> >> >> As before - this R-b likely would need dropping, ... >> >>> --- >>> changes in v8: >>> - drop checks from viridian_load_vcpu/domain_ctxt() >>> - drop check "value != 0" in HVM_PARAM_VIRIDIAN handler, laways return >>> -ENODEV for VIRIDIAN=n >> >> ... when more than just cosmetic changes are made. Jason, please can you >> indicate whether it's fine to retain? Yes. Reviewed-by: Jason Andryuk <jason.andryuk@amd.com> Thanks, Jason
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