Re: [PATCH v1 03/15] intel_iommu: Check for compatibility with IOMMUFD backed device when x-flts=on
On 6/18/25 4:14 AM, Duan, Zhenzhong wrote:
>
>> -Original Message-
>> From: Eric Auger
>> Subject: Re: [PATCH v1 03/15] intel_iommu: Check for compatibility with
>> IOMMUFD backed device when x-flts=on
>>
>> Hi Zhenzhong,
>>
>> On 6/6/25 12:04 PM, Zhenzhong Duan wrote:
>>> When vIOMMU is configured x-flts=on in scalable mode, stage-1 page table
>>> is passed to host to construct nested page table. We need to check
>>> compatibility of some critical IOMMU capabilities between vIOMMU and
>>> host IOMMU to ensure guest stage-1 page table could be used by host.
>>>
>>> For instance, vIOMMU supports stage-1 1GB huge page mapping, but host
>>> does not, then this IOMMUFD backed device should be failed.
>>>
>>> Signed-off-by: Yi Liu
>>> Signed-off-by: Zhenzhong Duan
>>> ---
>>> hw/i386/intel_iommu_internal.h | 1 +
>>> hw/i386/intel_iommu.c | 28
>>> 2 files changed, 29 insertions(+)
>>>
>>> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
>>> index e8b211e8b0..2cda744786 100644
>>> --- a/hw/i386/intel_iommu_internal.h
>>> +++ b/hw/i386/intel_iommu_internal.h
>>> @@ -191,6 +191,7 @@
>>> #define VTD_ECAP_PT (1ULL << 6)
>>> #define VTD_ECAP_SC (1ULL << 7)
>>> #define VTD_ECAP_MHMV (15ULL << 20)
>>> +#define VTD_ECAP_NEST (1ULL << 26)
>>> #define VTD_ECAP_SRS(1ULL << 31)
>>> #define VTD_ECAP_PASID (1ULL << 40)
>>> #define VTD_ECAP_SMTS (1ULL << 43)
>>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>>> index a2f3250724..c42ef83ddc 100644
>>> --- a/hw/i386/intel_iommu.c
>>> +++ b/hw/i386/intel_iommu.c
>>> @@ -39,6 +39,7 @@
>>> #include "kvm/kvm_i386.h"
>>> #include "migration/vmstate.h"
>>> #include "trace.h"
>>> +#include "system/iommufd.h"
>>>
>>> /* context entry operations */
>>> #define VTD_CE_GET_RID2PASID(ce) \
>>> @@ -4361,6 +4362,33 @@ static bool vtd_check_hiod(IntelIOMMUState *s,
>> HostIOMMUDevice *hiod,
>>> return true;
>>> }
>>>
>>> +#ifdef CONFIG_IOMMUFD
>> is it requested?
> Yes, windows build needs it.
> iommu_hw_info_vtd and IOMMU_HW_INFO_TYPE_INTEL_VTD are defined in
> linux/iommufd.h,
which is a linux dep
> meanwhile all below check take effect only when IOMMUFD is supported.
OK. I tried to remove #imply IOMMUFD in hw/i386/Kconfig and I did not
get any error but well I did not build for Windows.
Eric
>
> Thanks
> Zhenzhong
>
>> Cheers
>>
>> Eric
>>> +struct HostIOMMUDeviceCaps *caps = &hiod->caps;
>>> +struct iommu_hw_info_vtd *vtd = &caps->vendor_caps.vtd;
>>> +
>>> +/* Remaining checks are all stage-1 translation specific */
>>> +if (!object_dynamic_cast(OBJECT(hiod),
>> TYPE_HOST_IOMMU_DEVICE_IOMMUFD)) {
>>> +error_setg(errp, "Need IOMMUFD backend when x-flts=on");
>>> +return false;
>>> +}
>>> +
>>> +if (caps->type != IOMMU_HW_INFO_TYPE_INTEL_VTD) {
>>> +error_setg(errp, "Incompatible host platform IOMMU type %d",
>>> + caps->type);
>>> +return false;
>>> +}
>>> +
>>> +if (!(vtd->ecap_reg & VTD_ECAP_NEST)) {
>>> +error_setg(errp, "Host IOMMU doesn't support nested translation");
>>> +return false;
>>> +}
>>> +
>>> +if (s->fs1gp && !(vtd->cap_reg & VTD_CAP_FS1GP)) {
>>> +error_setg(errp, "Stage-1 1GB huge page is unsupported by host
>>> IOMMU");
>>> +return false;
>>> +}
>>> +#endif
>>> +
>>> error_setg(errp, "host device is uncompatible with stage-1
>>> translation");
>>> return false;
>>> }
RE: [PATCH v1 03/15] intel_iommu: Check for compatibility with IOMMUFD backed device when x-flts=on
>-Original Message-
>From: Eric Auger
>Subject: Re: [PATCH v1 03/15] intel_iommu: Check for compatibility with
>IOMMUFD backed device when x-flts=on
>
>Hi Zhenzhong,
>
>On 6/6/25 12:04 PM, Zhenzhong Duan wrote:
>> When vIOMMU is configured x-flts=on in scalable mode, stage-1 page table
>> is passed to host to construct nested page table. We need to check
>> compatibility of some critical IOMMU capabilities between vIOMMU and
>> host IOMMU to ensure guest stage-1 page table could be used by host.
>>
>> For instance, vIOMMU supports stage-1 1GB huge page mapping, but host
>> does not, then this IOMMUFD backed device should be failed.
>>
>> Signed-off-by: Yi Liu
>> Signed-off-by: Zhenzhong Duan
>> ---
>> hw/i386/intel_iommu_internal.h | 1 +
>> hw/i386/intel_iommu.c | 28
>> 2 files changed, 29 insertions(+)
>>
>> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
>> index e8b211e8b0..2cda744786 100644
>> --- a/hw/i386/intel_iommu_internal.h
>> +++ b/hw/i386/intel_iommu_internal.h
>> @@ -191,6 +191,7 @@
>> #define VTD_ECAP_PT (1ULL << 6)
>> #define VTD_ECAP_SC (1ULL << 7)
>> #define VTD_ECAP_MHMV (15ULL << 20)
>> +#define VTD_ECAP_NEST (1ULL << 26)
>> #define VTD_ECAP_SRS(1ULL << 31)
>> #define VTD_ECAP_PASID (1ULL << 40)
>> #define VTD_ECAP_SMTS (1ULL << 43)
>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>> index a2f3250724..c42ef83ddc 100644
>> --- a/hw/i386/intel_iommu.c
>> +++ b/hw/i386/intel_iommu.c
>> @@ -39,6 +39,7 @@
>> #include "kvm/kvm_i386.h"
>> #include "migration/vmstate.h"
>> #include "trace.h"
>> +#include "system/iommufd.h"
>>
>> /* context entry operations */
>> #define VTD_CE_GET_RID2PASID(ce) \
>> @@ -4361,6 +4362,33 @@ static bool vtd_check_hiod(IntelIOMMUState *s,
>HostIOMMUDevice *hiod,
>> return true;
>> }
>>
>> +#ifdef CONFIG_IOMMUFD
>is it requested?
Yes, windows build needs it.
iommu_hw_info_vtd and IOMMU_HW_INFO_TYPE_INTEL_VTD are defined in
linux/iommufd.h,
meanwhile all below check take effect only when IOMMUFD is supported.
Thanks
Zhenzhong
>
>Cheers
>
>Eric
>> +struct HostIOMMUDeviceCaps *caps = &hiod->caps;
>> +struct iommu_hw_info_vtd *vtd = &caps->vendor_caps.vtd;
>> +
>> +/* Remaining checks are all stage-1 translation specific */
>> +if (!object_dynamic_cast(OBJECT(hiod),
>TYPE_HOST_IOMMU_DEVICE_IOMMUFD)) {
>> +error_setg(errp, "Need IOMMUFD backend when x-flts=on");
>> +return false;
>> +}
>> +
>> +if (caps->type != IOMMU_HW_INFO_TYPE_INTEL_VTD) {
>> +error_setg(errp, "Incompatible host platform IOMMU type %d",
>> + caps->type);
>> +return false;
>> +}
>> +
>> +if (!(vtd->ecap_reg & VTD_ECAP_NEST)) {
>> +error_setg(errp, "Host IOMMU doesn't support nested translation");
>> +return false;
>> +}
>> +
>> +if (s->fs1gp && !(vtd->cap_reg & VTD_CAP_FS1GP)) {
>> +error_setg(errp, "Stage-1 1GB huge page is unsupported by host
>> IOMMU");
>> +return false;
>> +}
>> +#endif
>> +
>> error_setg(errp, "host device is uncompatible with stage-1
>> translation");
>> return false;
>> }
Re: [PATCH v1 03/15] intel_iommu: Check for compatibility with IOMMUFD backed device when x-flts=on
Hi Zhenzhong,
On 6/6/25 12:04 PM, Zhenzhong Duan wrote:
> When vIOMMU is configured x-flts=on in scalable mode, stage-1 page table
> is passed to host to construct nested page table. We need to check
> compatibility of some critical IOMMU capabilities between vIOMMU and
> host IOMMU to ensure guest stage-1 page table could be used by host.
>
> For instance, vIOMMU supports stage-1 1GB huge page mapping, but host
> does not, then this IOMMUFD backed device should be failed.
>
> Signed-off-by: Yi Liu
> Signed-off-by: Zhenzhong Duan
> ---
> hw/i386/intel_iommu_internal.h | 1 +
> hw/i386/intel_iommu.c | 28
> 2 files changed, 29 insertions(+)
>
> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> index e8b211e8b0..2cda744786 100644
> --- a/hw/i386/intel_iommu_internal.h
> +++ b/hw/i386/intel_iommu_internal.h
> @@ -191,6 +191,7 @@
> #define VTD_ECAP_PT (1ULL << 6)
> #define VTD_ECAP_SC (1ULL << 7)
> #define VTD_ECAP_MHMV (15ULL << 20)
> +#define VTD_ECAP_NEST (1ULL << 26)
> #define VTD_ECAP_SRS(1ULL << 31)
> #define VTD_ECAP_PASID (1ULL << 40)
> #define VTD_ECAP_SMTS (1ULL << 43)
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index a2f3250724..c42ef83ddc 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -39,6 +39,7 @@
> #include "kvm/kvm_i386.h"
> #include "migration/vmstate.h"
> #include "trace.h"
> +#include "system/iommufd.h"
>
> /* context entry operations */
> #define VTD_CE_GET_RID2PASID(ce) \
> @@ -4361,6 +4362,33 @@ static bool vtd_check_hiod(IntelIOMMUState *s,
> HostIOMMUDevice *hiod,
> return true;
> }
>
> +#ifdef CONFIG_IOMMUFD
is it requested?
Cheers
Eric
> +struct HostIOMMUDeviceCaps *caps = &hiod->caps;
> +struct iommu_hw_info_vtd *vtd = &caps->vendor_caps.vtd;
> +
> +/* Remaining checks are all stage-1 translation specific */
> +if (!object_dynamic_cast(OBJECT(hiod), TYPE_HOST_IOMMU_DEVICE_IOMMUFD)) {
> +error_setg(errp, "Need IOMMUFD backend when x-flts=on");
> +return false;
> +}
> +
> +if (caps->type != IOMMU_HW_INFO_TYPE_INTEL_VTD) {
> +error_setg(errp, "Incompatible host platform IOMMU type %d",
> + caps->type);
> +return false;
> +}
> +
> +if (!(vtd->ecap_reg & VTD_ECAP_NEST)) {
> +error_setg(errp, "Host IOMMU doesn't support nested translation");
> +return false;
> +}
> +
> +if (s->fs1gp && !(vtd->cap_reg & VTD_CAP_FS1GP)) {
> +error_setg(errp, "Stage-1 1GB huge page is unsupported by host
> IOMMU");
> +return false;
> +}
> +#endif
> +
> error_setg(errp, "host device is uncompatible with stage-1 translation");
> return false;
> }
[PATCH v1 03/15] intel_iommu: Check for compatibility with IOMMUFD backed device when x-flts=on
When vIOMMU is configured x-flts=on in scalable mode, stage-1 page table
is passed to host to construct nested page table. We need to check
compatibility of some critical IOMMU capabilities between vIOMMU and
host IOMMU to ensure guest stage-1 page table could be used by host.
For instance, vIOMMU supports stage-1 1GB huge page mapping, but host
does not, then this IOMMUFD backed device should be failed.
Signed-off-by: Yi Liu
Signed-off-by: Zhenzhong Duan
---
hw/i386/intel_iommu_internal.h | 1 +
hw/i386/intel_iommu.c | 28
2 files changed, 29 insertions(+)
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index e8b211e8b0..2cda744786 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -191,6 +191,7 @@
#define VTD_ECAP_PT (1ULL << 6)
#define VTD_ECAP_SC (1ULL << 7)
#define VTD_ECAP_MHMV (15ULL << 20)
+#define VTD_ECAP_NEST (1ULL << 26)
#define VTD_ECAP_SRS(1ULL << 31)
#define VTD_ECAP_PASID (1ULL << 40)
#define VTD_ECAP_SMTS (1ULL << 43)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index a2f3250724..c42ef83ddc 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -39,6 +39,7 @@
#include "kvm/kvm_i386.h"
#include "migration/vmstate.h"
#include "trace.h"
+#include "system/iommufd.h"
/* context entry operations */
#define VTD_CE_GET_RID2PASID(ce) \
@@ -4361,6 +4362,33 @@ static bool vtd_check_hiod(IntelIOMMUState *s,
HostIOMMUDevice *hiod,
return true;
}
+#ifdef CONFIG_IOMMUFD
+struct HostIOMMUDeviceCaps *caps = &hiod->caps;
+struct iommu_hw_info_vtd *vtd = &caps->vendor_caps.vtd;
+
+/* Remaining checks are all stage-1 translation specific */
+if (!object_dynamic_cast(OBJECT(hiod), TYPE_HOST_IOMMU_DEVICE_IOMMUFD)) {
+error_setg(errp, "Need IOMMUFD backend when x-flts=on");
+return false;
+}
+
+if (caps->type != IOMMU_HW_INFO_TYPE_INTEL_VTD) {
+error_setg(errp, "Incompatible host platform IOMMU type %d",
+ caps->type);
+return false;
+}
+
+if (!(vtd->ecap_reg & VTD_ECAP_NEST)) {
+error_setg(errp, "Host IOMMU doesn't support nested translation");
+return false;
+}
+
+if (s->fs1gp && !(vtd->cap_reg & VTD_CAP_FS1GP)) {
+error_setg(errp, "Stage-1 1GB huge page is unsupported by host IOMMU");
+return false;
+}
+#endif
+
error_setg(errp, "host device is uncompatible with stage-1 translation");
return false;
}
--
2.34.1
