[Xen-changelog] [xen staging] mem_access: Fix npfec.kind propagation

[p***@xen.org]

commit f736a3b7285384529de932055856be0703f8ac20
Author: George Dunlap <***@citrix.com>
AuthorDate: Thu Sep 27 12:25:36 2018 +0100
Commit: Andrew Cooper <***@citrix.com>
CommitDate: Wed Oct 17 14:46:45 2018 +0100

mem_access: Fix npfec.kind propagation

The name of the "with_gla" flag is confusing; it has nothing to do
with the existence or lack thereof of a faulting GLA, but rather where
the fault originated. The npfec.kind value is always valid, and
should thus be propagated, regardless of whether gla_valid is set or
not.

In particular, gla_valid will never be set on AMD systems; but
npfec.kind will still be valid and should still be propagated.

Signed-off-by: Alexandru Isaila <***@bitdefender.com>
Signed-off-by: George Dunlap <***@citrix.com>
Acked-by: Andrew Cooper <***@citrix.com>
Reviewed-by: Alexandru Isaila <***@bitdefender.com>
Acked-by: Razvan Cojocaru <***@bitdefender.com>
---
xen/arch/x86/mm/mem_access.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index 2b5a6217db..2f1295e56a 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -228,16 +228,24 @@ bool p2m_mem_access_check(paddr_t gpa, unsigned long gla,
req->reason = VM_EVENT_REASON_MEM_ACCESS;
req->u.mem_access.gfn = gfn_x(gfn);
req->u.mem_access.offset = gpa & ((1 << PAGE_SHIFT) - 1);
+
if ( npfec.gla_valid )
{
req->u.mem_access.flags |= MEM_ACCESS_GLA_VALID;
req->u.mem_access.gla = gla;
+ }

- if ( npfec.kind == npfec_kind_with_gla )
- req->u.mem_access.flags |= MEM_ACCESS_FAULT_WITH_GLA;
- else if ( npfec.kind == npfec_kind_in_gpt )
- req->u.mem_access.flags |= MEM_ACCESS_FAULT_IN_GPT;
+ switch ( npfec.kind )
+ {
+ case npfec_kind_with_gla:
+ req->u.mem_access.flags |= MEM_ACCESS_FAULT_WITH_GLA;
+ break;
+
+ case npfec_kind_in_gpt:
+ req->u.mem_access.flags |= MEM_ACCESS_FAULT_IN_GPT;
+ break;
}
+
req->u.mem_access.flags |= npfec.read_access ? MEM_ACCESS_R : 0;
req->u.mem_access.flags |= npfec.write_access ? MEM_ACCESS_W : 0;
req->u.mem_access.flags |= npfec.insn_fetch ? MEM_ACCESS_X : 0;
--
generated by git-patchbot for /home/xen/git/xen.git#staging