@@ -31,7 +31,6 @@
#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>
@@ -48,6 +47,7 @@
#include <asm/kasan.h>
#include <asm/dma-mapping.h>
#include <asm/uv.h>
+#include <linux/virtio_anchor.h>
#include <linux/virtio_config.h>
pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
@@ -175,7 +175,7 @@ static void pv_init(void)
if (!is_prot_virt_guest())
return;
- platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
+ virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
/* make sure bounce buffers are shared */
swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
@@ -20,8 +20,8 @@
#include <linux/bitops.h>
#include <linux/dma-mapping.h>
#include <linux/virtio_config.h>
+#include <linux/virtio_anchor.h>
#include <linux/cc_platform.h>
-#include <linux/platform-feature.h>
#include <asm/tlbflush.h>
#include <asm/fixmap.h>
@@ -245,7 +245,7 @@ void __init sev_setup_arch(void)
swiotlb_adjust_size(size);
/* Set restricted memory access for virtio. */
- platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
+ virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
}
static unsigned long pg_level_to_pfn(int level, pte_t *kpte, pgprot_t *ret_prot)
@@ -1,6 +1,10 @@
# SPDX-License-Identifier: GPL-2.0-only
+config VIRTIO_ANCHOR
+ bool
+
config VIRTIO
tristate
+ select VIRTIO_ANCHOR
help
This option is selected by any driver which implements the virtio
bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
+obj-$(CONFIG_VIRTIO_ANCHOR) += virtio_anchor.o
obj-$(CONFIG_VIRTIO_PCI_LIB) += virtio_pci_modern_dev.o
obj-$(CONFIG_VIRTIO_PCI_LIB_LEGACY) += virtio_pci_legacy_dev.o
obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
@@ -2,10 +2,10 @@
#include <linux/virtio.h>
#include <linux/spinlock.h>
#include <linux/virtio_config.h>
+#include <linux/virtio_anchor.h>
#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. */
@@ -174,7 +174,7 @@ static int virtio_features_ok(struct virtio_device *dev)
might_sleep();
- if (platform_has(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS)) {
+ if (virtio_check_mem_acc_cb(dev)) {
if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
dev_warn(&dev->dev,
"device must provide VIRTIO_F_VERSION_1\n");
new file mode 100644
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/virtio.h>
+#include <linux/virtio_anchor.h>
+
+bool virtio_require_restricted_mem_acc(struct virtio_device *dev)
+{
+ return true;
+}
+EXPORT_SYMBOL_GPL(virtio_require_restricted_mem_acc);
+
+static bool virtio_no_restricted_mem_acc(struct virtio_device *dev)
+{
+ return false;
+}
+
+bool (*virtio_check_mem_acc_cb)(struct virtio_device *dev) =
+ virtio_no_restricted_mem_acc;
+EXPORT_SYMBOL_GPL(virtio_check_mem_acc_cb);
@@ -6,11 +6,7 @@
#include <asm/platform-feature.h>
/* The platform features are starting with the architecture specific ones. */
-
-/* Used to enable platform specific DMA handling for virtio devices. */
-#define PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS (0 + PLATFORM_ARCH_FEAT_N)
-
-#define PLATFORM_FEAT_N (1 + PLATFORM_ARCH_FEAT_N)
+#define PLATFORM_FEAT_N (0 + PLATFORM_ARCH_FEAT_N)
void platform_set(unsigned int feature);
void platform_clear(unsigned int feature);
new file mode 100644
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_VIRTIO_ANCHOR_H
+#define _LINUX_VIRTIO_ANCHOR_H
+
+#ifdef CONFIG_VIRTIO_ANCHOR
+struct virtio_device;
+
+bool virtio_require_restricted_mem_acc(struct virtio_device *dev);
+extern bool (*virtio_check_mem_acc_cb)(struct virtio_device *dev);
+
+static inline void virtio_set_mem_acc_cb(bool (*func)(struct virtio_device *))
+{
+ virtio_check_mem_acc_cb = func;
+}
+#else
+#define virtio_set_mem_acc_cb(func) do { } while (0)
+#endif
+
+#endif /* _LINUX_VIRTIO_ANCHOR_H */
@@ -52,12 +52,12 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
extern u64 xen_saved_max_mem_size;
#endif
-#include <linux/platform-feature.h>
+#include <linux/virtio_anchor.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);
+ virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
}
#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
Instead of having a global flag to require restricted memory access for all virtio devices, introduce a callback which can select that requirement on a per-device basis. For convenience add a common function returning always true, which can be used for use cases like SEV. Per default use a callback always returning false. As the callback needs to be set in early init code already, add a virtio anchor which is builtin in case virtio is enabled. Signed-off-by: Juergen Gross <jgross@suse.com> --- arch/s390/mm/init.c | 4 ++-- arch/x86/mm/mem_encrypt_amd.c | 4 ++-- drivers/virtio/Kconfig | 4 ++++ drivers/virtio/Makefile | 1 + drivers/virtio/virtio.c | 4 ++-- drivers/virtio/virtio_anchor.c | 18 ++++++++++++++++++ include/linux/platform-feature.h | 6 +----- include/linux/virtio_anchor.h | 19 +++++++++++++++++++ include/xen/xen.h | 4 ++-- 9 files changed, 51 insertions(+), 13 deletions(-) create mode 100644 drivers/virtio/virtio_anchor.c create mode 100644 include/linux/virtio_anchor.h