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* [PATCH v9 0/2] s390: virtio: let arch validate VIRTIO features
@ 2020-08-19 16:23 ` Pierre Morel
  0 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-19 16:23 UTC (permalink / raw)
  To: linux-kernel
  Cc: pasic, borntraeger, frankja, mst, jasowang, cohuck, kvm,
	linux-s390, virtualization, thomas.lendacky, david, linuxram,
	hca, gor

Hi all,

The goal of the series is to give a chance to the architecture
to validate VIRTIO device features.

in this respin:

The tests are back to virtio_finalize_features.

No more argument for the architecture callback which only reports
if the architecture needs guest memory access restrictions for
VIRTIO.


I renamed the callback to arch_has_restricted_virtio_memory_access,
and the config option to ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS.

Regards,
Pierre

Pierre Morel (2):
  virtio: let arch advertise guest's memory access restrictions
  s390: virtio: PV needs VIRTIO I/O device protection

 arch/s390/Kconfig             |  1 +
 arch/s390/mm/init.c           | 11 +++++++++++
 drivers/virtio/Kconfig        |  6 ++++++
 drivers/virtio/virtio.c       | 15 +++++++++++++++
 include/linux/virtio_config.h |  9 +++++++++
 5 files changed, 42 insertions(+)

-- 
2.25.1

Changelog

to v9:

- move virtio tests back to virtio_finalize_features
  (Connie)

- remove virtio device argument

to v8:

- refactoring by using an optional callback
  (Connie)

to v7:

- typo in warning message
  (Connie)
to v6:

- rewording warning messages
  (Connie, Halil)

to v5:

- return directly from S390 arch_validate_virtio_features()
  when the guest is not protected.
  (Connie)

- Somme rewording
  (Connie, Michael)

- moved back code from arch/s390/ ...kernel/uv.c to ...mm/init.c
  (Christian)

to v4:

- separate virtio and arch code
  (Pierre)

- moved code from arch/s390/mm/init.c to arch/s390/kernel/uv.c
  (as interpreted from Heiko's comment)

- moved validation inside the arch code
  (Connie)

- moved the call to arch validation before VIRTIO_F_1 test
  (Michael)

to v3:

- add warning
  (Connie, Christian)

- add comment
  (Connie)

- change hook name
  (Halil, Connie)

to v2:

- put the test in virtio_finalize_features()
  (Connie)

- put the test inside VIRTIO core
  (Jason)

- pass a virtio device as parameter
  (Halil)



^ permalink raw reply	[flat|nested] 14+ messages in thread
* [PATCH v9 0/2] s390: virtio: let arch validate VIRTIO features
@ 2020-08-19 16:23 ` Pierre Morel
  0 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-19 16:23 UTC (permalink / raw)
  To: linux-kernel
  Cc: gor, linux-s390, frankja, kvm, mst, cohuck, linuxram,
	virtualization, pasic, borntraeger, thomas.lendacky, hca, david

Hi all,

The goal of the series is to give a chance to the architecture
to validate VIRTIO device features.

in this respin:

The tests are back to virtio_finalize_features.

No more argument for the architecture callback which only reports
if the architecture needs guest memory access restrictions for
VIRTIO.


I renamed the callback to arch_has_restricted_virtio_memory_access,
and the config option to ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS.

Regards,
Pierre

Pierre Morel (2):
  virtio: let arch advertise guest's memory access restrictions
  s390: virtio: PV needs VIRTIO I/O device protection

 arch/s390/Kconfig             |  1 +
 arch/s390/mm/init.c           | 11 +++++++++++
 drivers/virtio/Kconfig        |  6 ++++++
 drivers/virtio/virtio.c       | 15 +++++++++++++++
 include/linux/virtio_config.h |  9 +++++++++
 5 files changed, 42 insertions(+)

-- 
2.25.1

Changelog

to v9:

- move virtio tests back to virtio_finalize_features
  (Connie)

- remove virtio device argument

to v8:

- refactoring by using an optional callback
  (Connie)

to v7:

- typo in warning message
  (Connie)
to v6:

- rewording warning messages
  (Connie, Halil)

to v5:

- return directly from S390 arch_validate_virtio_features()
  when the guest is not protected.
  (Connie)

- Somme rewording
  (Connie, Michael)

- moved back code from arch/s390/ ...kernel/uv.c to ...mm/init.c
  (Christian)

to v4:

- separate virtio and arch code
  (Pierre)

- moved code from arch/s390/mm/init.c to arch/s390/kernel/uv.c
  (as interpreted from Heiko's comment)

- moved validation inside the arch code
  (Connie)

- moved the call to arch validation before VIRTIO_F_1 test
  (Michael)

to v3:

- add warning
  (Connie, Christian)

- add comment
  (Connie)

- change hook name
  (Halil, Connie)

to v2:

- put the test in virtio_finalize_features()
  (Connie)

- put the test inside VIRTIO core
  (Jason)

- pass a virtio device as parameter
  (Halil)


_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 14+ messages in thread
* [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions
  2020-08-19 16:23 ` Pierre Morel
@ 2020-08-19 16:23   ` Pierre Morel
  -1 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-19 16:23 UTC (permalink / raw)
  To: linux-kernel
  Cc: pasic, borntraeger, frankja, mst, jasowang, cohuck, kvm,
	linux-s390, virtualization, thomas.lendacky, david, linuxram,
	hca, gor

An architecture may restrict host access to guest memory.

Provide a new Kconfig entry the architecture can select,
CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
the arch_has_restricted_virtio_memory_access callback to advertise
VIRTIO common code when the architecture restricts memory access
from the host.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 drivers/virtio/Kconfig        |  6 ++++++
 drivers/virtio/virtio.c       | 15 +++++++++++++++
 include/linux/virtio_config.h |  9 +++++++++
 3 files changed, 30 insertions(+)

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 5809e5f5b157..509f3b4d8ba1 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -6,6 +6,12 @@ config VIRTIO
 	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
 	  or CONFIG_S390_GUEST.
 
+config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+	bool
+	help
+	  This option is selected by any architecture enforcing
+	  VIRTIO_F_IOMMU_PLATFORM
+
 menuconfig VIRTIO_MENU
 	bool "Virtio drivers"
 	default y
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index a977e32a88f2..57ca41d77b09 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -176,6 +176,21 @@ int virtio_finalize_features(struct virtio_device *dev)
 	if (ret)
 		return ret;
 
+	ret = arch_has_restricted_virtio_memory_access();
+	if (ret) {
+		if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
+			dev_warn(&dev->dev,
+				 "device must provide VIRTIO_F_VERSION_1\n");
+			return -ENODEV;
+		}
+
+		if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) {
+			dev_warn(&dev->dev,
+				 "device must provide VIRTIO_F_IOMMU_PLATFORM\n");
+			return -ENODEV;
+		}
+	}
+
 	if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
 		return 0;
 
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index bb4cc4910750..e380664642b4 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -459,4 +459,13 @@ static inline void virtio_cwrite64(struct virtio_device *vdev,
 		_r;							\
 	})
 
+#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+int arch_has_restricted_virtio_memory_access(void);
+#else
+static inline int arch_has_restricted_virtio_memory_access(void)
+{
+	return 0;
+}
+#endif /* CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS */
+
 #endif /* _LINUX_VIRTIO_CONFIG_H */
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions
@ 2020-08-19 16:23   ` Pierre Morel
  0 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-19 16:23 UTC (permalink / raw)
  To: linux-kernel
  Cc: gor, linux-s390, frankja, kvm, mst, cohuck, linuxram,
	virtualization, pasic, borntraeger, thomas.lendacky, hca, david

An architecture may restrict host access to guest memory.

Provide a new Kconfig entry the architecture can select,
CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
the arch_has_restricted_virtio_memory_access callback to advertise
VIRTIO common code when the architecture restricts memory access
from the host.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 drivers/virtio/Kconfig        |  6 ++++++
 drivers/virtio/virtio.c       | 15 +++++++++++++++
 include/linux/virtio_config.h |  9 +++++++++
 3 files changed, 30 insertions(+)

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 5809e5f5b157..509f3b4d8ba1 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -6,6 +6,12 @@ config VIRTIO
 	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
 	  or CONFIG_S390_GUEST.
 
+config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+	bool
+	help
+	  This option is selected by any architecture enforcing
+	  VIRTIO_F_IOMMU_PLATFORM
+
 menuconfig VIRTIO_MENU
 	bool "Virtio drivers"
 	default y
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index a977e32a88f2..57ca41d77b09 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -176,6 +176,21 @@ int virtio_finalize_features(struct virtio_device *dev)
 	if (ret)
 		return ret;
 
+	ret = arch_has_restricted_virtio_memory_access();
+	if (ret) {
+		if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
+			dev_warn(&dev->dev,
+				 "device must provide VIRTIO_F_VERSION_1\n");
+			return -ENODEV;
+		}
+
+		if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) {
+			dev_warn(&dev->dev,
+				 "device must provide VIRTIO_F_IOMMU_PLATFORM\n");
+			return -ENODEV;
+		}
+	}
+
 	if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
 		return 0;
 
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index bb4cc4910750..e380664642b4 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -459,4 +459,13 @@ static inline void virtio_cwrite64(struct virtio_device *vdev,
 		_r;							\
 	})
 
+#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+int arch_has_restricted_virtio_memory_access(void);
+#else
+static inline int arch_has_restricted_virtio_memory_access(void)
+{
+	return 0;
+}
+#endif /* CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS */
+
 #endif /* _LINUX_VIRTIO_CONFIG_H */
-- 
2.25.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH v9 2/2] s390: virtio: PV needs VIRTIO I/O device protection
  2020-08-19 16:23 ` Pierre Morel
@ 2020-08-19 16:23   ` Pierre Morel
  -1 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-19 16:23 UTC (permalink / raw)
  To: linux-kernel
  Cc: pasic, borntraeger, frankja, mst, jasowang, cohuck, kvm,
	linux-s390, virtualization, thomas.lendacky, david, linuxram,
	hca, gor

If protected virtualization is active on s390, VIRTIO has retricted
access to the guest memory.
Define CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS and export
arch_has_restricted_virtio_memory_access to advertize VIRTIO if that's
the case, preventing a host error on access attempt.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 arch/s390/Kconfig   |  1 +
 arch/s390/mm/init.c | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9cfd8de907cb..c12422c26389 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -820,6 +820,7 @@ menu "Virtualization"
 config PROTECTED_VIRTUALIZATION_GUEST
 	def_bool n
 	prompt "Protected virtualization guest support"
+	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
 	help
 	  Select this option, if you want to be able to run this
 	  kernel as a protected virtualization KVM guest.
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 6dc7c3b60ef6..8febd73ed6ca 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -45,6 +45,7 @@
 #include <asm/kasan.h>
 #include <asm/dma-mapping.h>
 #include <asm/uv.h>
+#include <linux/virtio_config.h>
 
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 
@@ -161,6 +162,16 @@ bool force_dma_unencrypted(struct device *dev)
 	return is_prot_virt_guest();
 }
 
+#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+
+int arch_has_restricted_virtio_memory_access(void)
+{
+	return is_prot_virt_guest();
+}
+EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
+
+#endif
+
 /* protected virtualization */
 static void pv_init(void)
 {
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [PATCH v9 2/2] s390: virtio: PV needs VIRTIO I/O device protection
@ 2020-08-19 16:23   ` Pierre Morel
  0 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-19 16:23 UTC (permalink / raw)
  To: linux-kernel
  Cc: gor, linux-s390, frankja, kvm, mst, cohuck, linuxram,
	virtualization, pasic, borntraeger, thomas.lendacky, hca, david

If protected virtualization is active on s390, VIRTIO has retricted
access to the guest memory.
Define CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS and export
arch_has_restricted_virtio_memory_access to advertize VIRTIO if that's
the case, preventing a host error on access attempt.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 arch/s390/Kconfig   |  1 +
 arch/s390/mm/init.c | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9cfd8de907cb..c12422c26389 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -820,6 +820,7 @@ menu "Virtualization"
 config PROTECTED_VIRTUALIZATION_GUEST
 	def_bool n
 	prompt "Protected virtualization guest support"
+	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
 	help
 	  Select this option, if you want to be able to run this
 	  kernel as a protected virtualization KVM guest.
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 6dc7c3b60ef6..8febd73ed6ca 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -45,6 +45,7 @@
 #include <asm/kasan.h>
 #include <asm/dma-mapping.h>
 #include <asm/uv.h>
+#include <linux/virtio_config.h>
 
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 
@@ -161,6 +162,16 @@ bool force_dma_unencrypted(struct device *dev)
 	return is_prot_virt_guest();
 }
 
+#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+
+int arch_has_restricted_virtio_memory_access(void)
+{
+	return is_prot_virt_guest();
+}
+EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
+
+#endif
+
 /* protected virtualization */
 static void pv_init(void)
 {
-- 
2.25.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions
  2020-08-19 16:23   ` Pierre Morel
@ 2020-08-21 11:59     ` Cornelia Huck
  -1 siblings, 0 replies; 14+ messages in thread
From: Cornelia Huck @ 2020-08-21 11:59 UTC (permalink / raw)
  To: Pierre Morel
  Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm,
	linux-s390, virtualization, thomas.lendacky, david, linuxram,
	hca, gor

On Wed, 19 Aug 2020 18:23:17 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> An architecture may restrict host access to guest memory.

"e.g. IBM s390 Secure Execution or AMD SEV"

Just to make clearer what you are referring to?

> 
> Provide a new Kconfig entry the architecture can select,
> CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
> the arch_has_restricted_virtio_memory_access callback to advertise

s/advertise/advertise to/

> VIRTIO common code when the architecture restricts memory access
> from the host.

"The common code can then fail the probe for any device where
VIRTIO_F_IOMMU_PLATFORM is required, but not set."

?

> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  drivers/virtio/Kconfig        |  6 ++++++
>  drivers/virtio/virtio.c       | 15 +++++++++++++++
>  include/linux/virtio_config.h |  9 +++++++++
>  3 files changed, 30 insertions(+)
> 
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 5809e5f5b157..509f3b4d8ba1 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -6,6 +6,12 @@ config VIRTIO
>  	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
>  	  or CONFIG_S390_GUEST.
>  
> +config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
> +	bool
> +	help
> +	  This option is selected by any architecture enforcing
> +	  VIRTIO_F_IOMMU_PLATFORM

"This option is selected if the architecture may need to enforce
VIRTIO_F_IOMMU_PLATFORM."

?

> +
>  menuconfig VIRTIO_MENU
>  	bool "Virtio drivers"
>  	default y

(...)

Reviewed-by: Cornelia Huck <cohuck@redhat.com>


^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions
@ 2020-08-21 11:59     ` Cornelia Huck
  0 siblings, 0 replies; 14+ messages in thread
From: Cornelia Huck @ 2020-08-21 11:59 UTC (permalink / raw)
  To: Pierre Morel
  Cc: gor, linux-s390, frankja, kvm, mst, linuxram, linux-kernel,
	virtualization, pasic, borntraeger, thomas.lendacky, hca, david

On Wed, 19 Aug 2020 18:23:17 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> An architecture may restrict host access to guest memory.

"e.g. IBM s390 Secure Execution or AMD SEV"

Just to make clearer what you are referring to?

> 
> Provide a new Kconfig entry the architecture can select,
> CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
> the arch_has_restricted_virtio_memory_access callback to advertise

s/advertise/advertise to/

> VIRTIO common code when the architecture restricts memory access
> from the host.

"The common code can then fail the probe for any device where
VIRTIO_F_IOMMU_PLATFORM is required, but not set."

?

> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  drivers/virtio/Kconfig        |  6 ++++++
>  drivers/virtio/virtio.c       | 15 +++++++++++++++
>  include/linux/virtio_config.h |  9 +++++++++
>  3 files changed, 30 insertions(+)
> 
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 5809e5f5b157..509f3b4d8ba1 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -6,6 +6,12 @@ config VIRTIO
>  	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
>  	  or CONFIG_S390_GUEST.
>  
> +config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
> +	bool
> +	help
> +	  This option is selected by any architecture enforcing
> +	  VIRTIO_F_IOMMU_PLATFORM

"This option is selected if the architecture may need to enforce
VIRTIO_F_IOMMU_PLATFORM."

?

> +
>  menuconfig VIRTIO_MENU
>  	bool "Virtio drivers"
>  	default y

(...)

Reviewed-by: Cornelia Huck <cohuck@redhat.com>

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 2/2] s390: virtio: PV needs VIRTIO I/O device protection
  2020-08-19 16:23   ` Pierre Morel
@ 2020-08-21 12:05     ` Cornelia Huck
  -1 siblings, 0 replies; 14+ messages in thread
From: Cornelia Huck @ 2020-08-21 12:05 UTC (permalink / raw)
  To: Pierre Morel
  Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm,
	linux-s390, virtualization, thomas.lendacky, david, linuxram,
	hca, gor

On Wed, 19 Aug 2020 18:23:18 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> If protected virtualization is active on s390, VIRTIO has retricted

s/retricted/only restricted/

> access to the guest memory.
> Define CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS and export
> arch_has_restricted_virtio_memory_access to advertize VIRTIO if that's
> the case, preventing a host error on access attempt.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  arch/s390/Kconfig   |  1 +
>  arch/s390/mm/init.c | 11 +++++++++++
>  2 files changed, 12 insertions(+)

(...)

> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index 6dc7c3b60ef6..8febd73ed6ca 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -45,6 +45,7 @@
>  #include <asm/kasan.h>
>  #include <asm/dma-mapping.h>
>  #include <asm/uv.h>
> +#include <linux/virtio_config.h>

I don't think you need this include anymore.

>  
>  pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
>  

(...)

With the nit fixed,

Reviewed-by: Cornelia Huck <cohuck@redhat.com>


^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 2/2] s390: virtio: PV needs VIRTIO I/O device protection
@ 2020-08-21 12:05     ` Cornelia Huck
  0 siblings, 0 replies; 14+ messages in thread
From: Cornelia Huck @ 2020-08-21 12:05 UTC (permalink / raw)
  To: Pierre Morel
  Cc: gor, linux-s390, frankja, kvm, mst, linuxram, linux-kernel,
	virtualization, pasic, borntraeger, thomas.lendacky, hca, david

On Wed, 19 Aug 2020 18:23:18 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> If protected virtualization is active on s390, VIRTIO has retricted

s/retricted/only restricted/

> access to the guest memory.
> Define CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS and export
> arch_has_restricted_virtio_memory_access to advertize VIRTIO if that's
> the case, preventing a host error on access attempt.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  arch/s390/Kconfig   |  1 +
>  arch/s390/mm/init.c | 11 +++++++++++
>  2 files changed, 12 insertions(+)

(...)

> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index 6dc7c3b60ef6..8febd73ed6ca 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -45,6 +45,7 @@
>  #include <asm/kasan.h>
>  #include <asm/dma-mapping.h>
>  #include <asm/uv.h>
> +#include <linux/virtio_config.h>

I don't think you need this include anymore.

>  
>  pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
>  

(...)

With the nit fixed,

Reviewed-by: Cornelia Huck <cohuck@redhat.com>

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 2/2] s390: virtio: PV needs VIRTIO I/O device protection
  2020-08-21 12:05     ` Cornelia Huck
@ 2020-08-21 13:06       ` Pierre Morel
  -1 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-21 13:06 UTC (permalink / raw)
  To: Cornelia Huck
  Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm,
	linux-s390, virtualization, thomas.lendacky, david, linuxram,
	hca, gor



On 2020-08-21 14:05, Cornelia Huck wrote:
> On Wed, 19 Aug 2020 18:23:18 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> If protected virtualization is active on s390, VIRTIO has retricted
> 
> s/retricted/only restricted/
> 
>> access to the guest memory.
>> Define CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS and export
>> arch_has_restricted_virtio_memory_access to advertize VIRTIO if that's
>> the case, preventing a host error on access attempt.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   arch/s390/Kconfig   |  1 +
>>   arch/s390/mm/init.c | 11 +++++++++++
>>   2 files changed, 12 insertions(+)
> 
> (...)
> 
>> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
>> index 6dc7c3b60ef6..8febd73ed6ca 100644
>> --- a/arch/s390/mm/init.c
>> +++ b/arch/s390/mm/init.c
>> @@ -45,6 +45,7 @@
>>   #include <asm/kasan.h>
>>   #include <asm/dma-mapping.h>
>>   #include <asm/uv.h>
>> +#include <linux/virtio_config.h>
> 
> I don't think you need this include anymore.

right,
> 
>>   
>>   pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
>>   
> 
> (...)
> 
> With the nit fixed,
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

Thanks,

Pierre

-- 
Pierre Morel
IBM Lab Boeblingen

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 2/2] s390: virtio: PV needs VIRTIO I/O device protection
@ 2020-08-21 13:06       ` Pierre Morel
  0 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-21 13:06 UTC (permalink / raw)
  To: Cornelia Huck
  Cc: gor, linux-s390, frankja, kvm, mst, linuxram, linux-kernel,
	virtualization, pasic, borntraeger, thomas.lendacky, hca, david



On 2020-08-21 14:05, Cornelia Huck wrote:
> On Wed, 19 Aug 2020 18:23:18 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> If protected virtualization is active on s390, VIRTIO has retricted
> 
> s/retricted/only restricted/
> 
>> access to the guest memory.
>> Define CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS and export
>> arch_has_restricted_virtio_memory_access to advertize VIRTIO if that's
>> the case, preventing a host error on access attempt.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   arch/s390/Kconfig   |  1 +
>>   arch/s390/mm/init.c | 11 +++++++++++
>>   2 files changed, 12 insertions(+)
> 
> (...)
> 
>> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
>> index 6dc7c3b60ef6..8febd73ed6ca 100644
>> --- a/arch/s390/mm/init.c
>> +++ b/arch/s390/mm/init.c
>> @@ -45,6 +45,7 @@
>>   #include <asm/kasan.h>
>>   #include <asm/dma-mapping.h>
>>   #include <asm/uv.h>
>> +#include <linux/virtio_config.h>
> 
> I don't think you need this include anymore.

right,
> 
>>   
>>   pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
>>   
> 
> (...)
> 
> With the nit fixed,
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

Thanks,

Pierre

-- 
Pierre Morel
IBM Lab Boeblingen
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions
  2020-08-21 11:59     ` Cornelia Huck
@ 2020-08-21 13:08       ` Pierre Morel
  -1 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-21 13:08 UTC (permalink / raw)
  To: Cornelia Huck
  Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm,
	linux-s390, virtualization, thomas.lendacky, david, linuxram,
	hca, gor



On 2020-08-21 13:59, Cornelia Huck wrote:
> On Wed, 19 Aug 2020 18:23:17 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> An architecture may restrict host access to guest memory.
> 
> "e.g. IBM s390 Secure Execution or AMD SEV"
> 
> Just to make clearer what you are referring to?

yes, thanks

> 
>>
>> Provide a new Kconfig entry the architecture can select,
>> CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
>> the arch_has_restricted_virtio_memory_access callback to advertise
> 
> s/advertise/advertise to/

OK

> 
>> VIRTIO common code when the architecture restricts memory access
>> from the host.
> 
> "The common code can then fail the probe for any device where
> VIRTIO_F_IOMMU_PLATFORM is required, but not set."
> 
> ?

Yes, better thanks

> 
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   drivers/virtio/Kconfig        |  6 ++++++
>>   drivers/virtio/virtio.c       | 15 +++++++++++++++
>>   include/linux/virtio_config.h |  9 +++++++++
>>   3 files changed, 30 insertions(+)
>>
>> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
>> index 5809e5f5b157..509f3b4d8ba1 100644
>> --- a/drivers/virtio/Kconfig
>> +++ b/drivers/virtio/Kconfig
>> @@ -6,6 +6,12 @@ config VIRTIO
>>   	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
>>   	  or CONFIG_S390_GUEST.
>>   
>> +config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
>> +	bool
>> +	help
>> +	  This option is selected by any architecture enforcing
>> +	  VIRTIO_F_IOMMU_PLATFORM
> 
> "This option is selected if the architecture may need to enforce
> VIRTIO_F_IOMMU_PLATFORM."
> 
> ?

yes, better thanks

> 
>> +
>>   menuconfig VIRTIO_MENU
>>   	bool "Virtio drivers"
>>   	default y
> 
> (...)
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

I will make the rewordings.

Thanks,
Pierre

-- 
Pierre Morel
IBM Lab Boeblingen

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions
@ 2020-08-21 13:08       ` Pierre Morel
  0 siblings, 0 replies; 14+ messages in thread
From: Pierre Morel @ 2020-08-21 13:08 UTC (permalink / raw)
  To: Cornelia Huck
  Cc: gor, linux-s390, frankja, kvm, mst, linuxram, linux-kernel,
	virtualization, pasic, borntraeger, thomas.lendacky, hca, david



On 2020-08-21 13:59, Cornelia Huck wrote:
> On Wed, 19 Aug 2020 18:23:17 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> An architecture may restrict host access to guest memory.
> 
> "e.g. IBM s390 Secure Execution or AMD SEV"
> 
> Just to make clearer what you are referring to?

yes, thanks

> 
>>
>> Provide a new Kconfig entry the architecture can select,
>> CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
>> the arch_has_restricted_virtio_memory_access callback to advertise
> 
> s/advertise/advertise to/

OK

> 
>> VIRTIO common code when the architecture restricts memory access
>> from the host.
> 
> "The common code can then fail the probe for any device where
> VIRTIO_F_IOMMU_PLATFORM is required, but not set."
> 
> ?

Yes, better thanks

> 
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   drivers/virtio/Kconfig        |  6 ++++++
>>   drivers/virtio/virtio.c       | 15 +++++++++++++++
>>   include/linux/virtio_config.h |  9 +++++++++
>>   3 files changed, 30 insertions(+)
>>
>> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
>> index 5809e5f5b157..509f3b4d8ba1 100644
>> --- a/drivers/virtio/Kconfig
>> +++ b/drivers/virtio/Kconfig
>> @@ -6,6 +6,12 @@ config VIRTIO
>>   	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
>>   	  or CONFIG_S390_GUEST.
>>   
>> +config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
>> +	bool
>> +	help
>> +	  This option is selected by any architecture enforcing
>> +	  VIRTIO_F_IOMMU_PLATFORM
> 
> "This option is selected if the architecture may need to enforce
> VIRTIO_F_IOMMU_PLATFORM."
> 
> ?

yes, better thanks

> 
>> +
>>   menuconfig VIRTIO_MENU
>>   	bool "Virtio drivers"
>>   	default y
> 
> (...)
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

I will make the rewordings.

Thanks,
Pierre

-- 
Pierre Morel
IBM Lab Boeblingen
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 14+ messages in thread
end of thread, other threads:[~2020-08-21 13:08 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-19 16:23 [PATCH v9 0/2] s390: virtio: let arch validate VIRTIO features Pierre Morel
2020-08-19 16:23 ` Pierre Morel
2020-08-19 16:23 ` [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions Pierre Morel
2020-08-19 16:23   ` Pierre Morel
2020-08-21 11:59   ` Cornelia Huck
2020-08-21 11:59     ` Cornelia Huck
2020-08-21 13:08     ` Pierre Morel
2020-08-21 13:08       ` Pierre Morel
2020-08-19 16:23 ` [PATCH v9 2/2] s390: virtio: PV needs VIRTIO I/O device protection Pierre Morel
2020-08-19 16:23   ` Pierre Morel
2020-08-21 12:05   ` Cornelia Huck
2020-08-21 12:05     ` Cornelia Huck
2020-08-21 13:06     ` Pierre Morel
2020-08-21 13:06       ` Pierre Morel

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