[RFC,01/11] Drivers: hv: vmbus: Always use HV_HYP_PAGE_SIZE for gpadl

Commit Message

Boqun Feng July 21, 2020, 1:41 a.m. UTC

Since the hypervisor always uses 4K as its page size, the size of PFNs
used for gpadl should be HV_HYP_PAGE_SIZE rather than PAGE_SIZE, so
adjust this accordingly as the preparation for supporting 16K/64K page
size guests.

Signed-off-by: Boqun Feng <[e-mail]>
---
 drivers/hv/channel.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

Comments

Wei Liu July 21, 2020, 3:22 p.m. UTC | #1

On Tue, Jul 21, 2020 at 09:41:25AM +0800, Boqun Feng wrote:
> Since the hypervisor always uses 4K as its page size, the size of PFNs
> used for gpadl should be HV_HYP_PAGE_SIZE rather than PAGE_SIZE, so
> adjust this accordingly as the preparation for supporting 16K/64K page
> size guests.

It may be worth calling out there is no change on x86 because
HV_HYP_PAGE_SHIFT and PAGE_SHIFT are of the same value there.

Wei.

Boqun Feng July 22, 2020, 11:20 p.m. UTC | #2

On Tue, Jul 21, 2020 at 03:22:18PM +0000, Wei Liu wrote:
> On Tue, Jul 21, 2020 at 09:41:25AM +0800, Boqun Feng wrote:
> > Since the hypervisor always uses 4K as its page size, the size of PFNs
> > used for gpadl should be HV_HYP_PAGE_SIZE rather than PAGE_SIZE, so
> > adjust this accordingly as the preparation for supporting 16K/64K page
> > size guests.
> 
> It may be worth calling out there is no change on x86 because
> HV_HYP_PAGE_SHIFT and PAGE_SHIFT are of the same value there.
> 

Sure, I will call it out in the commit log of the next version, thanks!

Regards,
Boqun

> Wei.

Patch

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 23f358cb7f49..b4378d9ae6ca 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -21,9 +21,6 @@ 
 
 #include "hyperv_vmbus.h"
 
-#define NUM_PAGES_SPANNED(addr, len) \
-((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
-
 static unsigned long virt_to_hvpfn(void *addr)
 {
 	phys_addr_t paddr;
@@ -34,7 +31,7 @@  static unsigned long virt_to_hvpfn(void *addr)
 	else
 		paddr = __pa(addr);
 
-	return  paddr >> PAGE_SHIFT;
+	return  paddr >> HV_HYP_PAGE_SHIFT;
 }
 
 /*
@@ -305,7 +302,7 @@  static int create_gpadl_header(void *kbuffer, u32 size,
 
 	int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 
-	pagecount = size >> PAGE_SHIFT;
+	pagecount = size >> HV_HYP_PAGE_SHIFT;
 
 	/* do we need a gpadl body msg */
 	pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
@@ -335,7 +332,7 @@  static int create_gpadl_header(void *kbuffer, u32 size,
 		gpadl_header->range[0].byte_count = size;
 		for (i = 0; i < pfncount; i++)
 			gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
-				kbuffer + PAGE_SIZE * i);
+				kbuffer + HV_HYP_PAGE_SIZE * i);
 		*msginfo = msgheader;
 
 		pfnsum = pfncount;
@@ -387,7 +384,7 @@  static int create_gpadl_header(void *kbuffer, u32 size,
 			 */
 			for (i = 0; i < pfncurr; i++)
 				gpadl_body->pfn[i] = virt_to_hvpfn(
-					kbuffer + PAGE_SIZE * (pfnsum + i));
+					kbuffer + HV_HYP_PAGE_SIZE * (pfnsum + i));
 
 			/* add to msg header */
 			list_add_tail(&msgbody->msglistentry,
@@ -416,7 +413,7 @@  static int create_gpadl_header(void *kbuffer, u32 size,
 		gpadl_header->range[0].byte_count = size;
 		for (i = 0; i < pagecount; i++)
 			gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
-				kbuffer + PAGE_SIZE * i);
+				kbuffer + HV_HYP_PAGE_SIZE * i);
 
 		*msginfo = msgheader;
 	}