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authorJuergen Gross <jgross@suse.com>2022-06-02 22:23:49 +0300
committerJuergen Gross <jgross@suse.com>2022-06-06 17:07:30 +0300
commitfa1f57421e0b1c57843902c89728f823abc32f02 (patch)
treea7cfcba922c86058156d997e07180b269b321c34
parentd6aca3504c7ded5f4f46957e3685b9344d9743dd (diff)
downloadlinux-fa1f57421e0b1c57843902c89728f823abc32f02.tar.xz
xen/virtio: Enable restricted memory access using Xen grant mappings
In order to support virtio in Xen guests add a config option XEN_VIRTIO enabling the user to specify whether in all Xen guests virtio should be able to access memory via Xen grant mappings only on the host side. Also set PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS feature from the guest initialization code on Arm and x86 if CONFIG_XEN_VIRTIO is enabled. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/1654197833-25362-5-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
-rw-r--r--arch/arm/xen/enlighten.c2
-rw-r--r--arch/x86/xen/enlighten_hvm.c2
-rw-r--r--arch/x86/xen/enlighten_pv.c2
-rw-r--r--drivers/xen/Kconfig11
-rw-r--r--include/xen/xen.h8
5 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 07eb69f9e7df..1f9c3ba32833 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -443,6 +443,8 @@ static int __init xen_guest_init(void)
if (!xen_domain())
return 0;
+ xen_set_restricted_virtio_memory_access();
+
if (!acpi_disabled)
xen_acpi_guest_init();
else
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index 517a9d8d8f94..8b71b1dd7639 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -195,6 +195,8 @@ static void __init xen_hvm_guest_init(void)
if (xen_pv_domain())
return;
+ xen_set_restricted_virtio_memory_access();
+
init_hvm_pv_info();
reserve_shared_info();
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index f33a4421e7cd..e3297b15701c 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -109,6 +109,8 @@ static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
static void __init xen_pv_init_platform(void)
{
+ xen_set_restricted_virtio_memory_access();
+
populate_extra_pte(fix_to_virt(FIX_PARAVIRT_BOOTMAP));
set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info);
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 313a9127fd5c..a7bd8ce7a1d2 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -339,4 +339,15 @@ config XEN_GRANT_DMA_OPS
bool
select DMA_OPS
+config XEN_VIRTIO
+ bool "Xen virtio support"
+ depends on VIRTIO
+ select XEN_GRANT_DMA_OPS
+ help
+ Enable virtio support for running as Xen guest. Depending on the
+ guest type this will require special support on the backend side
+ (qemu or kernel, depending on the virtio device types used).
+
+ If in doubt, say n.
+
endmenu
diff --git a/include/xen/xen.h b/include/xen/xen.h
index a99bab817523..0780a81e140d 100644
--- a/include/xen/xen.h
+++ b/include/xen/xen.h
@@ -52,6 +52,14 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
extern u64 xen_saved_max_mem_size;
#endif
+#include <linux/platform-feature.h>
+
+static inline void xen_set_restricted_virtio_memory_access(void)
+{
+ if (IS_ENABLED(CONFIG_XEN_VIRTIO) && xen_domain())
+ platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
+}
+
#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages);
void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages);