PING!
The patch repairs a bug with VMWARE, which has been reported by several
users. All of them have confirmed the patch is working. And VMWARE has
acked the patch. What else do you need to take it? It is available for
over a month now!
Juergen
On 01/12/2015 06:15 AM, Juergen Gross wrote:
VMWare seems not to emulate the PAT MSR correctly: reaeding
MSR_IA32_CR_PAT returns 0 even after writing another value to it.
Detect this bug and don't use the read value if it is 0.
Commit bd809af16e3ab1f8d55b3e2928c47c67e2a865d2 ("x86: Enable PAT to
use cache mode translation tables") triggers this VMWare bug when the
kernel is booted as a VMWare guest.
Reported-by: Jongman Heo <jongman....@samsung.com>
Signed-off-by: Juergen Gross <jgr...@suse.com>
Tested-by: Jongman Heo <jongman....@samsung.com>
Acked-by: Alok N Kataria <akata...@vmware.com>
---
arch/x86/mm/pat.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index edf299c..7ac6869 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -234,8 +234,13 @@ void pat_init(void)
PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC);
/* Boot CPU check */
- if (!boot_pat_state)
+ if (!boot_pat_state) {
rdmsrl(MSR_IA32_CR_PAT, boot_pat_state);
+ if (!boot_pat_state) {
+ pat_disable("PAT read returns always zero, disabled.");
+ return;
+ }
+ }
wrmsrl(MSR_IA32_CR_PAT, pat);
--
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