Re: [PATCH v7 5/9] powerpc/pseries: flush SLB contents on SLB MCE errors.

On 08/08/2018 02:34 PM, Nicholas Piggin wrote:

On Tue, 07 Aug 2018 19:47:14 +0530
Mahesh J Salgaonkar [off-list ref] wrote:

quoted

From: Mahesh Salgaonkar <redacted>

On pseries, as of today system crashes if we get a machine check
exceptions due to SLB errors. These are soft errors and can be fixed by
flushing the SLBs so the kernel can continue to function instead of
system crash. We do this in real mode before turning on MMU. Otherwise
we would run into nested machine checks. This patch now fetches the
rtas error log in real mode and flushes the SLBs on SLB errors.

Signed-off-by: Mahesh Salgaonkar <redacted>
Signed-off-by: Michal Suchanek <redacted>
---

Changes in V7:
- Fold Michal's patch into this patch.
- Handle MSR_RI=0 and evil context case in MC handler.
---

quoted

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index cb796724a6fc..e89f675f1b5e 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c

@@ -145,6 +145,12 @@ void slb_flush_and_rebolt(void)
 	get_paca()->slb_cache_ptr = 0;
 }
 
+void slb_flush_and_rebolt_realmode(void)
+{
+	__slb_flush_and_rebolt();
+	get_paca()->slb_cache_ptr = 0;
+}
+
 void slb_vmalloc_update(void)
 {
 	unsigned long vflags;

Can you use this patch for the SLB flush?

https://patchwork.ozlabs.org/patch/953034/

Will use your v2.

Thanks,
-Mahesh.

Thanks,
Nick