Juergen Gross
2022-Apr-27 15:33 UTC
[PATCH v2 2/2] virtio: replace arch_has_restricted_virtio_memory_access()
Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
with platform_has() and a new platform feature
PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS.
Signed-off-by: Juergen Gross <jgross at suse.com>
---
V2:
- move setting of PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS in SEV case
to sev_setup_arch().
---
arch/s390/Kconfig | 1 -
arch/s390/mm/init.c | 13 +++----------
arch/x86/Kconfig | 1 -
arch/x86/kernel/cpu/mshyperv.c | 5 ++++-
arch/x86/mm/mem_encrypt.c | 6 ------
arch/x86/mm/mem_encrypt_amd.c | 4 ++++
drivers/virtio/Kconfig | 6 ------
drivers/virtio/virtio.c | 5 ++---
include/linux/platform-feature.h | 3 ++-
include/linux/virtio_config.h | 9 ---------
10 files changed, 15 insertions(+), 38 deletions(-)
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index e084c72104f8..f97a22ae69a8 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -772,7 +772,6 @@ 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 86ffd0d51fd5..2c3b451813ed 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -31,6 +31,7 @@
#include <linux/cma.h>
#include <linux/gfp.h>
#include <linux/dma-direct.h>
+#include <linux/platform-feature.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/pgalloc.h>
@@ -168,22 +169,14 @@ 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)
{
if (!is_prot_virt_guest())
return;
+ platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
+
/* make sure bounce buffers are shared */
swiotlb_force = SWIOTLB_FORCE;
swiotlb_init(1);
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b0142e01002e..20ac72546ae4 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1515,7 +1515,6 @@ config X86_CPA_STATISTICS
config X86_MEM_ENCRYPT
select ARCH_HAS_FORCE_DMA_UNENCRYPTED
select DYNAMIC_PHYSICAL_MASK
- select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
def_bool n
config AMD_MEM_ENCRYPT
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 4b67094215bb..965518b9d14b 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -19,6 +19,7 @@
#include <linux/i8253.h>
#include <linux/random.h>
#include <linux/swiotlb.h>
+#include <linux/platform-feature.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
@@ -347,8 +348,10 @@ static void __init ms_hyperv_init_platform(void)
#endif
/* Isolation VMs are unenlightened SEV-based VMs, thus this check: */
if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
- if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE)
+ if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE) {
cc_set_vendor(CC_VENDOR_HYPERV);
+ platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
+ }
}
}
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 50d209939c66..9b6a7c98b2b1 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -76,9 +76,3 @@ void __init mem_encrypt_init(void)
print_mem_encrypt_feature_info();
}
-
-int arch_has_restricted_virtio_memory_access(void)
-{
- return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT);
-}
-EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index 6169053c2854..39b71084d36b 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -21,6 +21,7 @@
#include <linux/dma-mapping.h>
#include <linux/virtio_config.h>
#include <linux/cc_platform.h>
+#include <linux/platform-feature.h>
#include <asm/tlbflush.h>
#include <asm/fixmap.h>
@@ -206,6 +207,9 @@ void __init sev_setup_arch(void)
size = total_mem * 6 / 100;
size = clamp_val(size, IO_TLB_DEFAULT_SIZE, SZ_1G);
swiotlb_adjust_size(size);
+
+ /* Set restricted memory access for virtio. */
+ platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
}
static unsigned long pg_level_to_pfn(int level, pte_t *kpte, pgprot_t
*ret_prot)
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index b5adf6abd241..a6dc8b5846fe 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -6,12 +6,6 @@ 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 if the architecture may need to enforce
- VIRTIO_F_ACCESS_PLATFORM
-
config VIRTIO_PCI_LIB
tristate
help
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 22f15f444f75..371e16b18381 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -5,6 +5,7 @@
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/of.h>
+#include <linux/platform-feature.h>
#include <uapi/linux/virtio_ids.h>
/* Unique numbering for virtio devices. */
@@ -170,12 +171,10 @@ EXPORT_SYMBOL_GPL(virtio_add_status);
static int virtio_features_ok(struct virtio_device *dev)
{
unsigned status;
- int ret;
might_sleep();
- ret = arch_has_restricted_virtio_memory_access();
- if (ret) {
+ if (platform_has(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS)) {
if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
dev_warn(&dev->dev,
"device must provide VIRTIO_F_VERSION_1\n");
diff --git a/include/linux/platform-feature.h b/include/linux/platform-feature.h
index 6ed859928b97..5e2f08554b38 100644
--- a/include/linux/platform-feature.h
+++ b/include/linux/platform-feature.h
@@ -6,7 +6,8 @@
#include <asm/platform-feature.h>
/* The platform features are starting with the architecture specific ones. */
-#define PLATFORM_FEAT_N (0 + PLATFORM_ARCH_FEAT_N)
+#define PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS (0 + PLATFORM_ARCH_FEAT_N)
+#define PLATFORM_FEAT_N (1 + PLATFORM_ARCH_FEAT_N)
void platform_set(unsigned int feature);
void platform_clear(unsigned int feature);
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index b341dd62aa4d..79498298519d 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -559,13 +559,4 @@ 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 */
--
2.34.1
Michael Kelley (LINUX)
2022-Apr-27 16:30 UTC
[PATCH v2 2/2] virtio: replace arch_has_restricted_virtio_memory_access()
From: Juergen Gross <jgross at suse.com> Sent: Wednesday, April 27, 2022 8:34 AM> > Instead of using arch_has_restricted_virtio_memory_access() together > with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those > with platform_has() and a new platform feature > PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS. > > Signed-off-by: Juergen Gross <jgross at suse.com> > --- > V2: > - move setting of PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS in SEV case > to sev_setup_arch(). > --- > arch/s390/Kconfig | 1 - > arch/s390/mm/init.c | 13 +++---------- > arch/x86/Kconfig | 1 - > arch/x86/kernel/cpu/mshyperv.c | 5 ++++- > arch/x86/mm/mem_encrypt.c | 6 ------ > arch/x86/mm/mem_encrypt_amd.c | 4 ++++ > drivers/virtio/Kconfig | 6 ------ > drivers/virtio/virtio.c | 5 ++--- > include/linux/platform-feature.h | 3 ++- > include/linux/virtio_config.h | 9 --------- > 10 files changed, 15 insertions(+), 38 deletions(-) > > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index e084c72104f8..f97a22ae69a8 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -772,7 +772,6 @@ 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 86ffd0d51fd5..2c3b451813ed 100644 > --- a/arch/s390/mm/init.c > +++ b/arch/s390/mm/init.c > @@ -31,6 +31,7 @@ > #include <linux/cma.h> > #include <linux/gfp.h> > #include <linux/dma-direct.h> > +#include <linux/platform-feature.h> > #include <asm/processor.h> > #include <linux/uaccess.h> > #include <asm/pgalloc.h> > @@ -168,22 +169,14 @@ 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) > { > if (!is_prot_virt_guest()) > return; > > + platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); > + > /* make sure bounce buffers are shared */ > swiotlb_force = SWIOTLB_FORCE; > swiotlb_init(1); > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index b0142e01002e..20ac72546ae4 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -1515,7 +1515,6 @@ config X86_CPA_STATISTICS > config X86_MEM_ENCRYPT > select ARCH_HAS_FORCE_DMA_UNENCRYPTED > select DYNAMIC_PHYSICAL_MASK > - select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS > def_bool n > > config AMD_MEM_ENCRYPT > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c > index 4b67094215bb..965518b9d14b 100644 > --- a/arch/x86/kernel/cpu/mshyperv.c > +++ b/arch/x86/kernel/cpu/mshyperv.c > @@ -19,6 +19,7 @@ > #include <linux/i8253.h> > #include <linux/random.h> > #include <linux/swiotlb.h> > +#include <linux/platform-feature.h> > #include <asm/processor.h> > #include <asm/hypervisor.h> > #include <asm/hyperv-tlfs.h> > @@ -347,8 +348,10 @@ static void __init ms_hyperv_init_platform(void) > #endif > /* Isolation VMs are unenlightened SEV-based VMs, thus this check: */ > if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { > - if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE) > + if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE) { > cc_set_vendor(CC_VENDOR_HYPERV); > + > platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); > + } > } > } >Unless I'm misunderstanding something, the Hyper-V specific change isn't needed. Hyper-V doesn't support virtio in the first place, so it's a bit unexpected be setting a virtio-related flag in Hyper-V code. Also, Hyper-V guests call sev_setup_arch() with CC_ATTR_GUEST_MEM_ENCRYPT set, so this virtio-related flag will get set anyway via that path. Michael> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index 50d209939c66..9b6a7c98b2b1 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -76,9 +76,3 @@ void __init mem_encrypt_init(void) > > print_mem_encrypt_feature_info(); > } > - > -int arch_has_restricted_virtio_memory_access(void) > -{ > - return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT); > -} > -EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access); > diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c > index 6169053c2854..39b71084d36b 100644 > --- a/arch/x86/mm/mem_encrypt_amd.c > +++ b/arch/x86/mm/mem_encrypt_amd.c > @@ -21,6 +21,7 @@ > #include <linux/dma-mapping.h> > #include <linux/virtio_config.h> > #include <linux/cc_platform.h> > +#include <linux/platform-feature.h> > > #include <asm/tlbflush.h> > #include <asm/fixmap.h> > @@ -206,6 +207,9 @@ void __init sev_setup_arch(void) > size = total_mem * 6 / 100; > size = clamp_val(size, IO_TLB_DEFAULT_SIZE, SZ_1G); > swiotlb_adjust_size(size); > + > + /* Set restricted memory access for virtio. */ > + platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); > } > > static unsigned long pg_level_to_pfn(int level, pte_t *kpte, pgprot_t *ret_prot) > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig > index b5adf6abd241..a6dc8b5846fe 100644 > --- a/drivers/virtio/Kconfig > +++ b/drivers/virtio/Kconfig > @@ -6,12 +6,6 @@ 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 if the architecture may need to enforce > - VIRTIO_F_ACCESS_PLATFORM > - > config VIRTIO_PCI_LIB > tristate > help > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c > index 22f15f444f75..371e16b18381 100644 > --- a/drivers/virtio/virtio.c > +++ b/drivers/virtio/virtio.c > @@ -5,6 +5,7 @@ > #include <linux/module.h> > #include <linux/idr.h> > #include <linux/of.h> > +#include <linux/platform-feature.h> > #include <uapi/linux/virtio_ids.h> > > /* Unique numbering for virtio devices. */ > @@ -170,12 +171,10 @@ EXPORT_SYMBOL_GPL(virtio_add_status); > static int virtio_features_ok(struct virtio_device *dev) > { > unsigned status; > - int ret; > > might_sleep(); > > - ret = arch_has_restricted_virtio_memory_access(); > - if (ret) { > + if (platform_has(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS)) { > if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > dev_warn(&dev->dev, > "device must provide VIRTIO_F_VERSION_1\n"); > diff --git a/include/linux/platform-feature.h b/include/linux/platform-feature.h > index 6ed859928b97..5e2f08554b38 100644 > --- a/include/linux/platform-feature.h > +++ b/include/linux/platform-feature.h > @@ -6,7 +6,8 @@ > #include <asm/platform-feature.h> > > /* The platform features are starting with the architecture specific ones. */ > -#define PLATFORM_FEAT_N (0 + > PLATFORM_ARCH_FEAT_N) > +#define PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS (0 + > PLATFORM_ARCH_FEAT_N) > +#define PLATFORM_FEAT_N (1 + > PLATFORM_ARCH_FEAT_N) > > void platform_set(unsigned int feature); > void platform_clear(unsigned int feature); > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index b341dd62aa4d..79498298519d 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -559,13 +559,4 @@ 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 */ > -- > 2.34.1