Merge tag 'hyperv-next-signed-20211102' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Initial patch set for Hyper-V isolation VM support (Tianyu Lan)

 - Fix a warning on preemption (Vitaly Kuznetsov)

 - A bunch of misc cleanup patches

* tag 'hyperv-next-signed-20211102' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Protect set_hv_tscchange_cb() against getting preempted
  Drivers: hv : vmbus: Adding NULL pointer check
  x86/hyperv: Remove duplicate include
  x86/hyperv: Remove duplicated include in hv_init
  Drivers: hv: vmbus: Remove unused code to check for subchannels
  Drivers: hv: vmbus: Initialize VMbus ring buffer for Isolation VM
  Drivers: hv: vmbus: Add SNP support for VMbus channel initiate message
  x86/hyperv: Add ghcb hvcall support for SNP VM
  x86/hyperv: Add Write/Read MSR registers via ghcb page
  Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in Isolation VM
  x86/hyperv: Add new hvcall guest address host visibility support
  x86/hyperv: Initialize shared memory boundary in the Isolation VM.
  x86/hyperv: Initialize GHCB page in Isolation VM

1 files changed, 44 insertions, 13 deletions

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 314015d9e912..71efacb90965 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 +196,50 @@ 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;
 
-	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, PAGE_KERNEL);
+		ring_info->ring_buffer = (struct hv_ring_buffer *)
+			vmap_pfn(pfns_wraparound, page_cnt * 2 - 1,
+				 PAGE_KERNEL);
+		kfree(pfns_wraparound);
 
-	kfree(pages_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;
+	}
 
-	if (!ring_info->ring_buffer)
-		return -ENOMEM;
 
 	ring_info->ring_buffer->read_index =
 		ring_info->ring_buffer->write_index = 0;