[PATCH v8 3/5] x86/mm: Make tdx_enc_status_changed() vmalloc address compatible

Kuppuswamy Sathyanarayanan
2022-06-09T02:53:05Z

set_memory_*crypted() APIs are used to change encryption or decryption
page attributes for the given address. It also by default support the
conversion for the vmalloc'ed memory address.

In TDX Guest, tdx_enc_status_changed() function is triggered by
set_memory_*crypted() APIs when converting memory from/to shared or
private. Internally this function uses __pa() for physical address
conversion, which breaks the vmalloc address compatibility of the
set_memory_*crypted() APIs.

So add support to fix the vmalloc'ed address compatibility issue.

Acked-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
arch/x86/coco/tdx/tdx.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 94542876f26a..445f58547776 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -15,6 +15,7 @@
#include <asm/idtentry.h>
#include <asm/irq_regs.h>
#include <asm/desc.h>
+#include <asm/io.h>

/* TDX module Call Leaf IDs */
#define TDX_GET_INFO 1
@@ -678,8 +679,14 @@ static bool try_accept_one(phys_addr_t *start, unsigned long len,
*/
static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
{
- phys_addr_t start = __pa(vaddr);
- phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE);
+ phys_addr_t start, end;
+
+ if (is_vmalloc_addr((void *)vaddr))
+ start = vmalloc_to_pfn((void *) vaddr) << PAGE_SHIFT;
+ else
+ start = __pa(vaddr);
+
+ end = start + numpages * PAGE_SIZE;

if (!enc) {
/* Set the shared (decrypted) bits: */
--
2.25.1