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)
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 <[email protected]>
---
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
On Wed, 19 Aug 2020 18:23:18 +0200
Pierre Morel <[email protected]> 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 <[email protected]>
> ---
> 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 <[email protected]>
On 2020-08-21 14:05, Cornelia Huck wrote:
> On Wed, 19 Aug 2020 18:23:18 +0200
> Pierre Morel <[email protected]> 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 <[email protected]>
>> ---
>> 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 <[email protected]>
>
Thanks,
Pierre
--
Pierre Morel
IBM Lab Boeblingen