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authorTianyu Lan <Tianyu.Lan@microsoft.com>2021-10-25 08:21:14 -0400
committerWei Liu <wei.liu@kernel.org>2021-10-28 11:26:36 +0000
commit9a8797722e4239242d0cb4cc4baa805df6ac979e (patch)
tree8cb351e1b1c93971e0eb1910ca9f9ed34151e16e /drivers/hv/ring_buffer.c
parentf2f136c05fb6093818a3b3fefcba46231ac66a62 (diff)
downloadlinux-9a8797722e4239242d0cb4cc4baa805df6ac979e.tar.bz2
Drivers: hv: vmbus: Initialize VMbus ring buffer for Isolation VM
VMbus ring buffer are shared with host and it's need to be accessed via extra address space of Isolation VM with AMD SNP support. This patch is to map the ring buffer address in extra address space via vmap_pfn(). Hyperv set memory host visibility hvcall smears data in the ring buffer and so reset the ring buffer memory to zero after mapping. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-10-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/hv/ring_buffer.c')
-rw-r--r--drivers/hv/ring_buffer.c55
1 files changed, 42 insertions, 13 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 314015d9e912..931802ae985c 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -17,6 +17,8 @@
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/prefetch.h>
+#include <linux/io.h>
+#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
@@ -183,8 +185,10 @@ void hv_ringbuffer_pre_init(struct vmbus_channel *channel)
int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
struct page *pages, u32 page_cnt, u32 max_pkt_size)
{
- int i;
struct page **pages_wraparound;
+ unsigned long *pfns_wraparound;
+ u64 pfn;
+ int i;
BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE));
@@ -192,23 +196,48 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
* First page holds struct hv_ring_buffer, do wraparound mapping for
* the rest.
*/
- pages_wraparound = kcalloc(page_cnt * 2 - 1, sizeof(struct page *),
- GFP_KERNEL);
- if (!pages_wraparound)
- return -ENOMEM;
+ if (hv_isolation_type_snp()) {
+ pfn = page_to_pfn(pages) +
+ PFN_DOWN(ms_hyperv.shared_gpa_boundary);
+
+ pfns_wraparound = kcalloc(page_cnt * 2 - 1,
+ sizeof(unsigned long), GFP_KERNEL);
+ if (!pfns_wraparound)
+ return -ENOMEM;
+
+ pfns_wraparound[0] = pfn;
+ for (i = 0; i < 2 * (page_cnt - 1); i++)
+ pfns_wraparound[i + 1] = pfn + i % (page_cnt - 1) + 1;
- pages_wraparound[0] = pages;
- for (i = 0; i < 2 * (page_cnt - 1); i++)
- pages_wraparound[i + 1] = &pages[i % (page_cnt - 1) + 1];
+ ring_info->ring_buffer = (struct hv_ring_buffer *)
+ vmap_pfn(pfns_wraparound, page_cnt * 2 - 1,
+ PAGE_KERNEL);
+ kfree(pfns_wraparound);
- ring_info->ring_buffer = (struct hv_ring_buffer *)
- vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP, PAGE_KERNEL);
+ if (!ring_info->ring_buffer)
+ return -ENOMEM;
+
+ /* Zero ring buffer after setting memory host visibility. */
+ memset(ring_info->ring_buffer, 0x00, PAGE_SIZE * page_cnt);
+ } else {
+ pages_wraparound = kcalloc(page_cnt * 2 - 1,
+ sizeof(struct page *),
+ GFP_KERNEL);
+
+ pages_wraparound[0] = pages;
+ for (i = 0; i < 2 * (page_cnt - 1); i++)
+ pages_wraparound[i + 1] =
+ &pages[i % (page_cnt - 1) + 1];
- kfree(pages_wraparound);
+ ring_info->ring_buffer = (struct hv_ring_buffer *)
+ vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP,
+ PAGE_KERNEL);
+ kfree(pages_wraparound);
+ if (!ring_info->ring_buffer)
+ return -ENOMEM;
+ }
- if (!ring_info->ring_buffer)
- return -ENOMEM;
ring_info->ring_buffer->read_index =
ring_info->ring_buffer->write_index = 0;