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Drivers: hv: vmbus: Remove second way of mapping ring buffers 

With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), it's no longer necessary to
have separate code paths for mapping VMBus ring buffers for
for normal VMs and for Confidential VMs.

As such, remove the code path that uses vmap_pfn(), and set
the protection flags argument to vmap() to account for the
difference between normal and Confidential VMs.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-10-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Michael Kelley 2023-03-26 06:52:04 -07:00 committed by Wei Liu
parent a5ddb74588
commit bb862397f4
1 changed files with 20 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
drivers/hv/ring_buffer.c
View File

@ -186,8 +186,6 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
struct page *pages, u32 page_cnt, u32 max_pkt_size)
{
struct page **pages_wraparound;
unsigned long *pfns_wraparound;
u64 pfn;
int i;
BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE));
@ -196,50 +194,30 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
* First page holds struct hv_ring_buffer, do wraparound mapping for
* the rest.
*/
if (hv_isolation_type_snp()) {
pfn = page_to_pfn(pages) +
PFN_DOWN(ms_hyperv.shared_gpa_boundary);
pages_wraparound = kcalloc(page_cnt * 2 - 1,
sizeof(struct page *),
GFP_KERNEL);
if (!pages_wraparound)
return -ENOMEM;
pfns_wraparound = kcalloc(page_cnt * 2 - 1,
sizeof(unsigned long), GFP_KERNEL);
if (!pfns_wraparound)
return -ENOMEM;
pages_wraparound[0] = pages;
for (i = 0; i < 2 * (page_cnt - 1); i++)
pages_wraparound[i + 1] =
&pages[i % (page_cnt - 1) + 1];
pfns_wraparound[0] = pfn;
for (i = 0; i < 2 * (page_cnt - 1); i++)
pfns_wraparound[i + 1] = pfn + i % (page_cnt - 1) + 1;
ring_info->ring_buffer = (struct hv_ring_buffer *)
vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP,
pgprot_decrypted(PAGE_KERNEL));
ring_info->ring_buffer = (struct hv_ring_buffer *)
vmap_pfn(pfns_wraparound, page_cnt * 2 - 1,
pgprot_decrypted(PAGE_KERNEL));
kfree(pfns_wraparound);
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);
if (!pages_wraparound)
return -ENOMEM;
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(pages_wraparound, page_cnt * 2 - 1, VM_MAP,
PAGE_KERNEL);
kfree(pages_wraparound);
if (!ring_info->ring_buffer)
return -ENOMEM;
}
kfree(pages_wraparound);
if (!ring_info->ring_buffer)
return -ENOMEM;
/*
* Ensure the header page is zero'ed since
* encryption status may have changed.
*/
memset(ring_info->ring_buffer, 0, HV_HYP_PAGE_SIZE);
ring_info->ring_buffer->read_index =
ring_info->ring_buffer->write_index = 0;