From bb862397f48fc79a1ea31b83a0bd8f1f913b4ab6 Mon Sep 17 00:00:00 2001 From: Michael Kelley Date: Sun, 26 Mar 2023 06:52:04 -0700 Subject: [PATCH] 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 Reviewed-by: Tianyu Lan Link: https://lore.kernel.org/r/1679838727-87310-10-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu --- drivers/hv/ring_buffer.c | 62 +++++++++++++--------------------------- 1 file changed, 20 insertions(+), 42 deletions(-) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 2111e97c3b63..3c9b02471760 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -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;