diff mbox series

[v2] x86: make Viridian support optional

Message ID 20250321092633.3982645-1-Sergiy_Kibrik@epam.com (mailing list archive)
State New
Headers show
Series [v2] x86: make Viridian support optional | expand

Commit Message

Sergiy Kibrik March 21, 2025, 9:26 a.m. UTC
Add config option HVM_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.

Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
CC: Alejandro Vallejo <alejandro.vallejo@cloud.com>
CC: Jan Beulich <jbeulich@suse.com>
---
changes in v2:
 - changed title in Kconfig & add help text
 - moved Kconfig changes to arch/x86/hvm/Kconfig
 - address review comments
---
 xen/arch/x86/hvm/Kconfig              | 10 ++++++++++
 xen/arch/x86/hvm/Makefile             |  2 +-
 xen/arch/x86/hvm/hvm.c                | 27 ++++++++++++++++++---------
 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 ++
 7 files changed, 42 insertions(+), 15 deletions(-)

Comments

Alejandro Vallejo March 21, 2025, 3:42 p.m. UTC | #1
On Fri Mar 21, 2025 at 9:26 AM GMT, Sergiy Kibrik wrote:
> Add config option HVM_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.
>
> Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
> CC: Alejandro Vallejo <alejandro.vallejo@cloud.com>
> CC: Jan Beulich <jbeulich@suse.com>
> ---
> changes in v2:
>  - changed title in Kconfig & add help text
>  - moved Kconfig changes to arch/x86/hvm/Kconfig
>  - address review comments
> ---
>  xen/arch/x86/hvm/Kconfig              | 10 ++++++++++
>  xen/arch/x86/hvm/Makefile             |  2 +-
>  xen/arch/x86/hvm/hvm.c                | 27 ++++++++++++++++++---------
>  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 ++
>  7 files changed, 42 insertions(+), 15 deletions(-)

LGTM

  Reviewed-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>

Cheers,
Alejandro
Jan Beulich March 24, 2025, 11:52 a.m. UTC | #2
On 21.03.2025 10:26, Sergiy Kibrik wrote:
> Add config option HVM_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.
> 
> Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
> CC: Alejandro Vallejo <alejandro.vallejo@cloud.com>
> CC: Jan Beulich <jbeulich@suse.com>
> ---
> changes in v2:
>  - changed title in Kconfig & add help text
>  - moved Kconfig changes to arch/x86/hvm/Kconfig
>  - address review comments
> ---
>  xen/arch/x86/hvm/Kconfig              | 10 ++++++++++
>  xen/arch/x86/hvm/Makefile             |  2 +-
>  xen/arch/x86/hvm/hvm.c                | 27 ++++++++++++++++++---------
>  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 ++
>  7 files changed, 42 insertions(+), 15 deletions(-)
> 
> diff --git a/xen/arch/x86/hvm/Kconfig b/xen/arch/x86/hvm/Kconfig
> index 2def0f98e2..9cdcc0d3cd 100644
> --- a/xen/arch/x86/hvm/Kconfig
> +++ b/xen/arch/x86/hvm/Kconfig
> @@ -63,6 +63,16 @@ config ALTP2M
>  
>  	  If unsure, stay with defaults.
>  
> +config HVM_VIRIDIAN
> +	bool "Hyper-V enlighnments for guests" if EXPERT

Nit: "enlightenments"

> --- a/xen/arch/x86/include/asm/hvm/hvm.h
> +++ b/xen/arch/x86/include/asm/hvm/hvm.h
> @@ -507,7 +507,8 @@ 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_HVM_VIRIDIAN) && \
> +    is_hvm_domain(d) && (viridian_feature_mask(d) & HVMPV_base_freq))

Nit: Missing an indenting blank on the latter line.

Will adjust while committing.

Jan
Jan Beulich March 24, 2025, 1:37 p.m. UTC | #3
On 21.03.2025 10:26, Sergiy Kibrik wrote:
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -695,9 +695,12 @@ int hvm_domain_initialise(struct domain *d,
>      if ( hvm_tsc_scaling_supported )
>          d->arch.hvm.tsc_scaling_ratio = hvm_default_tsc_scaling_ratio;
>  
> -    rc = viridian_domain_init(d);
> -    if ( rc )
> -        goto fail2;
> +    if ( is_viridian_domain(d) )
> +    {
> +        rc = viridian_domain_init(d);
> +        if ( rc )
> +            goto fail2;
> +    }

It is, aiui, this conditional initialization which causes

(XEN) [    9.136463] UBSAN: Undefined behaviour in arch/x86/hvm/viridian/viridian.c:1118:43
(XEN) [    9.136465] member access within null pointer of type 'const struct viridian_domain'
(XEN) [    9.136471] ----[ Xen-4.21-unstable  x86_64  debug=y ubsan=y  Not tainted ]----
(XEN) [    9.136473] CPU:    14
(XEN) [    9.136475] RIP:    e008:[<ffff82d04032e8a8>] common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xd9
(XEN) [    9.136480] RFLAGS: 0000000000010096   CONTEXT: hypervisor (d0v6)
(XEN) [    9.136484] rax: 0000000000000000   rbx: ffff8304761afb40   rcx: 0000000000000868
(XEN) [    9.136486] rdx: ffff8304761affd0   rsi: 0000000000000004   rdi: ffff8304761afb40
(XEN) [    9.136488] rbp: ffff8304761afb30   rsp: ffff8304761afb20   r8:  0000000000000006
(XEN) [    9.136490] r9:  00000000ffffffff   r10: 0000000000000000   r11: 0000000000000000
(XEN) [    9.136493] r12: ffff82d040913d22   r13: 0000000000000003   r14: ffff82d040b237a0
(XEN) [    9.136495] r15: 000000000000000f   cr0: 0000000080050033   cr4: 0000000000b526e0
(XEN) [    9.136497] cr3: 0000000308528000   cr2: 00007f24a0c9de28
(XEN) [    9.136499] fsb: 00007f24a3fd6b48   gsb: ffff8881b9b80000   gss: 0000000000000000
(XEN) [    9.136501] ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e010   cs: e008
(XEN) [    9.136505] Xen code around <ffff82d04032e8a8> (common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xd9):
(XEN) [    9.136507]  89 e5 41 54 53 48 89 fb <0f> 0b 48 8d 3d ff 92 37 00 e8 9d 99 00 00 48 85
(XEN) [    9.136572] Xen stack trace from rsp=ffff8304761afb20:
(XEN) [    9.136574]    0000000000000003 ffff82d040913d22 ffff8304761afb70 ffff82d04032ef58
(XEN) [    9.136578]    0000000000000202 ffff82d040911100 0000000000000000 0000000000000000
(XEN) [    9.136581]    ffff82d040b237a0 000000000000000f ffff8304761afbd0 ffff82d04032f3af
(XEN) [    9.136585]    ffff82d0406b8900 0000002b8000045e ffff82d040913d1e 0000000000000001
(XEN) [    9.136588]    ffff82d040b23703 000000000000000f ffff8304761afbc0 ffff830405d65000
(XEN) [    9.136592]    ffff8304761afd00 0000000000000000 ffff8304761afc18 ffff82d040418b9c
(XEN) [    9.136595]    0000000000000000 0000000000000000 0000000000000000 0000000000000000
(XEN) [    9.136598]    ffff82d040b23a88 00000000000002e8 ffff830401d6cfe0 ffff8304761afc98
(XEN) [    9.136602]    ffff82d04045fc14 00000000000002c0 ffff82d040b23a58 ffff8304761afd00
(XEN) [    9.136605]    ffff82d040418a0a ffff830405d65000 ffff82d040b23a88 0000000154381286
(XEN) [    9.136609]    0000000000000000 00383ffe00090672 0000000000001c78 fffffffffffffff4
(XEN) [    9.136612]    ffff830476161000 ffff8304761afdb0 ffff830405d65000 ffff8304761afd50
(XEN) [    9.136616]    ffff82d040630690 800000030847e127 0000000000000206 000000000000000e
(XEN) [    9.136619]    ffff82d040a00b44 ffff82d040a00b40 ffff82d040a00b44 ffff83047618f000
(XEN) [    9.136622]    00007f24a3c7a010 ffff8304761afef8 ffff8304761afef8 ffff8304761b5088
(XEN) [    9.136626]    00001c7800000580 ffff830483a24000 0000000000000001 00007f24a3c7a010
(XEN) [    9.136629]    0000000000000001 ffff830405d65000 00007f24a3c7a010 0000000000000001
(XEN) [    9.136633]    0000000000000021 0000000000000000 ffff8304761afe68 ffff82d0402c662f
(XEN) [    9.136636]    ffff8304761afd80 ffff82d0405a0fbb ffff830476161000 ffff8881b9b80000
(XEN) [    9.136640]    ffff8304761afdb8 ffff82d04052fdef ffff830476161000 ffff8881b9b80000
(XEN) [    9.136643] Xen call trace:
(XEN) [    9.136646]    [<ffff82d04032e8a8>] R common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xd9
(XEN) [    9.136648]    [<ffff82d04032ef58>] F __ubsan_handle_type_mismatch+0x135/0x48e
(XEN) [    9.136651]    [<ffff82d04032f3af>] F __ubsan_handle_type_mismatch_v1+0xfe/0x100
(XEN) [    9.136655]    [<ffff82d040418b9c>] F arch/x86/hvm/viridian/viridian.c#viridian_save_domain_ctxt+0x192/0x204
(XEN) [    9.136658]    [<ffff82d04045fc14>] F hvm_save+0x4d1/0x5c6
(XEN) [    9.136661]    [<ffff82d040630690>] F arch_do_domctl+0x2f8/0x51aa
(XEN) [    9.136664]    [<ffff82d0402c662f>] F do_domctl+0xc91/0x460d
(XEN) [    9.136667]    [<ffff82d04053ab70>] F pv_hypercall+0x6d6/0x834
(XEN) [    9.136669]    [<ffff82d0402012d3>] F lstar_enter+0x143/0x150
(XEN) [    9.136671] 
(XEN) [    9.136673] ================================================================================
(XEN) [    9.622282] 
(XEN) [    9.624469] ****************************************
(XEN) [    9.630471] Panic on CPU 14:
(XEN) [    9.634182] UBSAN failure detected
(XEN) [    9.638469] ****************************************

throughout tests on actual hardware in CI. And really I don't think it's just UB, but
rather a real NULL deref:

    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,
    };

and only then

    if ( !is_viridian_domain(d) )
        return 0;

Makes me wonder if this change was actually tested ... In any event I'm about to revert
it.

Jan
Andrew Cooper March 24, 2025, 1:45 p.m. UTC | #4
On 24/03/2025 1:37 pm, Jan Beulich wrote:
> On 21.03.2025 10:26, Sergiy Kibrik wrote:
>> --- a/xen/arch/x86/hvm/hvm.c
>> +++ b/xen/arch/x86/hvm/hvm.c
>> @@ -695,9 +695,12 @@ int hvm_domain_initialise(struct domain *d,
>>      if ( hvm_tsc_scaling_supported )
>>          d->arch.hvm.tsc_scaling_ratio = hvm_default_tsc_scaling_ratio;
>>  
>> -    rc = viridian_domain_init(d);
>> -    if ( rc )
>> -        goto fail2;
>> +    if ( is_viridian_domain(d) )
>> +    {
>> +        rc = viridian_domain_init(d);
>> +        if ( rc )
>> +            goto fail2;
>> +    }
> It is, aiui, this conditional initialization which causes
>
> (XEN) [    9.136463] UBSAN: Undefined behaviour in arch/x86/hvm/viridian/viridian.c:1118:43
> (XEN) [    9.136465] member access within null pointer of type 'const struct viridian_domain'
> (XEN) [    9.136471] ----[ Xen-4.21-unstable  x86_64  debug=y ubsan=y  Not tainted ]----
> (XEN) [    9.136473] CPU:    14
> (XEN) [    9.136475] RIP:    e008:[<ffff82d04032e8a8>] common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xd9
> (XEN) [    9.136480] RFLAGS: 0000000000010096   CONTEXT: hypervisor (d0v6)
> (XEN) [    9.136484] rax: 0000000000000000   rbx: ffff8304761afb40   rcx: 0000000000000868
> (XEN) [    9.136486] rdx: ffff8304761affd0   rsi: 0000000000000004   rdi: ffff8304761afb40
> (XEN) [    9.136488] rbp: ffff8304761afb30   rsp: ffff8304761afb20   r8:  0000000000000006
> (XEN) [    9.136490] r9:  00000000ffffffff   r10: 0000000000000000   r11: 0000000000000000
> (XEN) [    9.136493] r12: ffff82d040913d22   r13: 0000000000000003   r14: ffff82d040b237a0
> (XEN) [    9.136495] r15: 000000000000000f   cr0: 0000000080050033   cr4: 0000000000b526e0
> (XEN) [    9.136497] cr3: 0000000308528000   cr2: 00007f24a0c9de28
> (XEN) [    9.136499] fsb: 00007f24a3fd6b48   gsb: ffff8881b9b80000   gss: 0000000000000000
> (XEN) [    9.136501] ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e010   cs: e008
> (XEN) [    9.136505] Xen code around <ffff82d04032e8a8> (common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xd9):
> (XEN) [    9.136507]  89 e5 41 54 53 48 89 fb <0f> 0b 48 8d 3d ff 92 37 00 e8 9d 99 00 00 48 85
> (XEN) [    9.136572] Xen stack trace from rsp=ffff8304761afb20:
> (XEN) [    9.136574]    0000000000000003 ffff82d040913d22 ffff8304761afb70 ffff82d04032ef58
> (XEN) [    9.136578]    0000000000000202 ffff82d040911100 0000000000000000 0000000000000000
> (XEN) [    9.136581]    ffff82d040b237a0 000000000000000f ffff8304761afbd0 ffff82d04032f3af
> (XEN) [    9.136585]    ffff82d0406b8900 0000002b8000045e ffff82d040913d1e 0000000000000001
> (XEN) [    9.136588]    ffff82d040b23703 000000000000000f ffff8304761afbc0 ffff830405d65000
> (XEN) [    9.136592]    ffff8304761afd00 0000000000000000 ffff8304761afc18 ffff82d040418b9c
> (XEN) [    9.136595]    0000000000000000 0000000000000000 0000000000000000 0000000000000000
> (XEN) [    9.136598]    ffff82d040b23a88 00000000000002e8 ffff830401d6cfe0 ffff8304761afc98
> (XEN) [    9.136602]    ffff82d04045fc14 00000000000002c0 ffff82d040b23a58 ffff8304761afd00
> (XEN) [    9.136605]    ffff82d040418a0a ffff830405d65000 ffff82d040b23a88 0000000154381286
> (XEN) [    9.136609]    0000000000000000 00383ffe00090672 0000000000001c78 fffffffffffffff4
> (XEN) [    9.136612]    ffff830476161000 ffff8304761afdb0 ffff830405d65000 ffff8304761afd50
> (XEN) [    9.136616]    ffff82d040630690 800000030847e127 0000000000000206 000000000000000e
> (XEN) [    9.136619]    ffff82d040a00b44 ffff82d040a00b40 ffff82d040a00b44 ffff83047618f000
> (XEN) [    9.136622]    00007f24a3c7a010 ffff8304761afef8 ffff8304761afef8 ffff8304761b5088
> (XEN) [    9.136626]    00001c7800000580 ffff830483a24000 0000000000000001 00007f24a3c7a010
> (XEN) [    9.136629]    0000000000000001 ffff830405d65000 00007f24a3c7a010 0000000000000001
> (XEN) [    9.136633]    0000000000000021 0000000000000000 ffff8304761afe68 ffff82d0402c662f
> (XEN) [    9.136636]    ffff8304761afd80 ffff82d0405a0fbb ffff830476161000 ffff8881b9b80000
> (XEN) [    9.136640]    ffff8304761afdb8 ffff82d04052fdef ffff830476161000 ffff8881b9b80000
> (XEN) [    9.136643] Xen call trace:
> (XEN) [    9.136646]    [<ffff82d04032e8a8>] R common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xd9
> (XEN) [    9.136648]    [<ffff82d04032ef58>] F __ubsan_handle_type_mismatch+0x135/0x48e
> (XEN) [    9.136651]    [<ffff82d04032f3af>] F __ubsan_handle_type_mismatch_v1+0xfe/0x100
> (XEN) [    9.136655]    [<ffff82d040418b9c>] F arch/x86/hvm/viridian/viridian.c#viridian_save_domain_ctxt+0x192/0x204
> (XEN) [    9.136658]    [<ffff82d04045fc14>] F hvm_save+0x4d1/0x5c6
> (XEN) [    9.136661]    [<ffff82d040630690>] F arch_do_domctl+0x2f8/0x51aa
> (XEN) [    9.136664]    [<ffff82d0402c662f>] F do_domctl+0xc91/0x460d
> (XEN) [    9.136667]    [<ffff82d04053ab70>] F pv_hypercall+0x6d6/0x834
> (XEN) [    9.136669]    [<ffff82d0402012d3>] F lstar_enter+0x143/0x150
> (XEN) [    9.136671] 
> (XEN) [    9.136673] ================================================================================
> (XEN) [    9.622282] 
> (XEN) [    9.624469] ****************************************
> (XEN) [    9.630471] Panic on CPU 14:
> (XEN) [    9.634182] UBSAN failure detected
> (XEN) [    9.638469] ****************************************
>
> throughout tests on actual hardware in CI. And really I don't think it's just UB, but
> rather a real NULL deref:

This is a consequence of us turning on UBSAN generally in GitlabCI, and
will be the norm moving forward.

Nevertheless, "member access within null pointer of type $X" is very
clear cut.

~Andrew
diff mbox series

Patch

diff --git a/xen/arch/x86/hvm/Kconfig b/xen/arch/x86/hvm/Kconfig
index 2def0f98e2..9cdcc0d3cd 100644
--- a/xen/arch/x86/hvm/Kconfig
+++ b/xen/arch/x86/hvm/Kconfig
@@ -63,6 +63,16 @@  config ALTP2M
 
 	  If unsure, stay with defaults.
 
+config HVM_VIRIDIAN
+	bool "Hyper-V enlighnments for guests" if EXPERT
+	default y
+	help
+	  Support optimizations for Hyper-V guests such as faster hypercalls,
+	  efficient timer and interrupt handling, and enhanced paravirtualized
+	  I/O. 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 4c1fa5c6c2..6cc2e74fc4 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_HVM_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 5950f3160f..529068e80c 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -695,9 +695,12 @@  int hvm_domain_initialise(struct domain *d,
     if ( hvm_tsc_scaling_supported )
         d->arch.hvm.tsc_scaling_ratio = hvm_default_tsc_scaling_ratio;
 
-    rc = viridian_domain_init(d);
-    if ( rc )
-        goto fail2;
+    if ( is_viridian_domain(d) )
+    {
+        rc = viridian_domain_init(d);
+        if ( rc )
+            goto fail2;
+    }
 
     rc = alternative_call(hvm_funcs.domain_initialise, d);
     if ( rc != 0 )
@@ -733,7 +736,8 @@  void hvm_domain_relinquish_resources(struct domain *d)
     if ( hvm_funcs.nhvm_domain_relinquish_resources )
         alternative_vcall(hvm_funcs.nhvm_domain_relinquish_resources, d);
 
-    viridian_domain_deinit(d);
+    if ( is_viridian_domain(d) )
+        viridian_domain_deinit(d);
 
     ioreq_server_destroy_all(d);
 
@@ -1637,9 +1641,12 @@  int hvm_vcpu_initialise(struct vcpu *v)
          && (rc = nestedhvm_vcpu_initialise(v)) < 0 ) /* teardown: nestedhvm_vcpu_destroy */
         goto fail5;
 
-    rc = viridian_vcpu_init(v);
-    if ( rc )
-        goto fail6;
+    if ( is_viridian_domain(d) )
+    {
+        rc = viridian_vcpu_init(v);
+        if ( rc )
+            goto fail6;
+    }
 
     rc = ioreq_server_add_vcpu_all(d, v);
     if ( rc != 0 )
@@ -1669,13 +1676,15 @@  int hvm_vcpu_initialise(struct vcpu *v)
  fail2:
     hvm_vcpu_cacheattr_destroy(v);
  fail1:
-    viridian_vcpu_deinit(v);
+    if ( is_viridian_domain(d) )
+        viridian_vcpu_deinit(v);
     return rc;
 }
 
 void hvm_vcpu_destroy(struct vcpu *v)
 {
-    viridian_vcpu_deinit(v);
+    if ( is_viridian_domain(v->domain) )
+        viridian_vcpu_deinit(v);
 
     ioreq_server_remove_vcpu_all(v->domain, v);
 
diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 065b2aab5b..3d76ce3f0d 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -426,7 +426,8 @@  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:
@@ -442,7 +443,7 @@  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]);
@@ -1360,7 +1361,8 @@  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);
@@ -1373,7 +1375,8 @@  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 333501d5f2..07eec231f0 100644
--- a/xen/arch/x86/include/asm/hvm/domain.h
+++ b/xen/arch/x86/include/asm/hvm/domain.h
@@ -111,7 +111,9 @@  struct hvm_domain {
     /* hypervisor intercepted msix table */
     struct list_head       msixtbl_list;
 
+#ifdef CONFIG_HVM_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 963e820113..a836b2f4de 100644
--- a/xen/arch/x86/include/asm/hvm/hvm.h
+++ b/xen/arch/x86/include/asm/hvm/hvm.h
@@ -507,7 +507,8 @@  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_HVM_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 196fed6d5d..4c5a76a707 100644
--- a/xen/arch/x86/include/asm/hvm/vcpu.h
+++ b/xen/arch/x86/include/asm/hvm/vcpu.h
@@ -172,7 +172,9 @@  struct hvm_vcpu {
     /* Pending hw/sw interrupt (.vector = -1 means nothing pending). */
     struct x86_event     inject_event;
 
+#ifdef CONFIG_HVM_VIRIDIAN
     struct viridian_vcpu *viridian;
+#endif
 };
 
 #endif /* __ASM_X86_HVM_VCPU_H__ */