[PATCH] powerpc/pseries: hwpoison the pages upon hitting UE

[PATCH] powerpc/pseries: hwpoison the pages upon hitting UE

[Ganesh Goudar]

Add support to hwpoison the pages upon hitting machine check
exception.

This patch queues the address where UE is hit to percpu array
and schedules work to plumb it into memory poison infrastructure.

Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
---
 arch/powerpc/include/asm/mce.h       |  1 +
 arch/powerpc/kernel/mce_power.c      |  2 +-
 arch/powerpc/platforms/pseries/ras.c | 85 +++++++++++++++++++++++++++-
 3 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
index 17996bc9382b..ad47fa865324 100644
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -210,6 +210,7 @@ extern void release_mce_event(void);
 extern void machine_check_queue_event(void);
 extern void machine_check_print_event_info(struct machine_check_event *evt,
 					   bool user_mode, bool in_guest);
+unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr);
 #ifdef CONFIG_PPC_BOOK3S_64
 void flush_and_reload_slb(void);
 #endif /* CONFIG_PPC_BOOK3S_64 */
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index 6b800eec31f2..367fbfa2e835 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -36,7 +36,7 @@
  * Convert an address related to an mm to a PFN. NOTE: we are in real
  * mode, we could potentially race with page table updates.
  */
-static unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
+unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
 {
 	pte_t *ptep;
 	unsigned long flags;
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 452dcfd7e5dd..d689b5fa6354 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -41,6 +41,18 @@ static struct irq_work mce_errlog_process_work = {
 	.func = mce_process_errlog_event,
 };
 
+#ifdef CONFIG_MEMORY_FAILURE
+
+static void pseries_hwpoison_work_fn(struct work_struct *work);
+static DEFINE_PER_CPU(int, rtas_ue_count);
+static DEFINE_PER_CPU(unsigned long, rtas_ue_paddr[MAX_MC_EVT]);
+static DECLARE_WORK(hwpoison_work, pseries_hwpoison_work_fn);
+
+#define UE_EFFECTIVE_ADDR_PROVIDED	PPC_BIT8(1)
+#define UE_LOGICAL_ADDR_PROVIDED	PPC_BIT8(2)
+
+#endif /* CONFIG_MEMORY_FAILURE */
+
 #define EPOW_SENSOR_TOKEN	9
 #define EPOW_SENSOR_INDEX	0
 
@@ -707,6 +719,75 @@ static int mce_handle_error(struct rtas_error_log *errp)
 	return disposition;
 }
 
+#ifdef CONFIG_MEMORY_FAILURE
+
+static void pseries_hwpoison_work_fn(struct work_struct *work)
+{
+	unsigned long paddr;
+	int index;
+
+	while (__this_cpu_read(rtas_ue_count) > 0) {
+		index = __this_cpu_read(rtas_ue_count) - 1;
+		paddr = __this_cpu_read(rtas_ue_paddr[index]);
+		memory_failure(paddr >> PAGE_SHIFT, 0);
+		__this_cpu_dec(rtas_ue_count);
+	}
+}
+
+static void queue_ue_paddr(unsigned long paddr)
+{
+	int index;
+
+	index = __this_cpu_inc_return(rtas_ue_count) - 1;
+	if (index >= MAX_MC_EVT) {
+		__this_cpu_dec(rtas_ue_count);
+		return;
+	}
+	this_cpu_write(rtas_ue_paddr[index], paddr);
+	schedule_work(&hwpoison_work);
+}
+
+static void pseries_do_memory_failure(struct pt_regs *regs,
+				      struct pseries_mc_errorlog *mce_log)
+{
+	unsigned long paddr;
+
+	if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
+		paddr = be64_to_cpu(mce_log->logical_address);
+	} else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
+		unsigned long pfn;
+
+		pfn = addr_to_pfn(regs,
+				  be64_to_cpu(mce_log->effective_address));
+		if (pfn == ULONG_MAX)
+			return;
+		paddr = pfn << PAGE_SHIFT;
+	} else {
+		return;
+	}
+	queue_ue_paddr(paddr);
+}
+
+static void pseries_process_ue(struct pt_regs *regs,
+			       struct rtas_error_log *errp)
+{
+	struct pseries_errorlog *pseries_log;
+	struct pseries_mc_errorlog *mce_log;
+
+	if (!rtas_error_extended(errp))
+		return;
+
+	pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
+	if (!pseries_log)
+		return;
+
+	mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
+
+	if (mce_log->error_type == MC_ERROR_TYPE_UE)
+		pseries_do_memory_failure(regs, mce_log);
+}
+#endif /*CONFIG_MEMORY_FAILURE */
+
 /*
  * Process MCE rtas errlog event.
  */
@@ -764,7 +845,9 @@ static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
 		_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 		recovered = 1;
 	}
-
+#ifdef CONFIG_MEMORY_FAILURE
+	pseries_process_ue(regs, err);
+#endif
 	/* Queue irq work to log this rtas event later. */
 	irq_work_queue(&mce_errlog_process_work);
 
-- 
2.17.2

Re: powerpc/pseries: hwpoison the pages upon hitting UE

[Michael Ellerman]

On Mon, 2019-04-15 at 10:05:44 UTC, Ganesh Goudar wrote:
> Add support to hwpoison the pages upon hitting machine check
> exception.
> 
> This patch queues the address where UE is hit to percpu array
> and schedules work to plumb it into memory poison infrastructure.
> 
> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/7f177f9810ada8ec2e8b378eddbe2d91

cheers