From: James Morse <james.morse@arm.com>
To: linux-acpi@vger.kernel.org
Cc: Rafael Wysocki <rjw@rjwysocki.net>,
Tony Luck <tony.luck@intel.com>, Xie XiuQi <xiexiuqi@huawei.com>,
Marc Zyngier <marc.zyngier@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Dongjiu Geng <gengdongjiu@huawei.com>,
linux-mm@kvack.org, Borislav Petkov <bp@alien8.de>,
james.morse@arm.com, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org, Len Brown <lenb@kernel.org>
Subject: [PATCH v8 14/26] arm64: KVM/mm: Move SEA handling behind a single 'claim' interface
Date: Tue, 29 Jan 2019 18:48:50 +0000 [thread overview]
Message-ID: <20190129184902.102850-15-james.morse@arm.com> (raw)
In-Reply-To: <20190129184902.102850-1-james.morse@arm.com>
To split up APEIs in_nmi() path, the caller needs to always be
in_nmi(). Add a helper to do the work and claim the notification.
When KVM or the arch code takes an exception that might be a RAS
notification, it asks the APEI firmware-first code whether it wants
to claim the exception. A future kernel-first mechanism may be queried
afterwards, and claim the notification, otherwise we fall through
to the existing default behaviour.
The NOTIFY_SEA code was merged before considering multiple, possibly
interacting, NMI-like notifications and the need to consider kernel
first in the future. Make the 'claiming' behaviour explicit.
Restructuring the APEI code to allow multiple NMI-like notifications
means any notification that might interrupt interrupts-masked
code must always be wrapped in nmi_enter()/nmi_exit(). This will
allow APEI to use in_nmi() to use the right fixmap entries.
Mask SError over this window to prevent an asynchronous RAS error
arriving and tripping 'nmi_enter()'s BUG_ON(in_nmi()).
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
---
Why does apei_claim_sea() take a pt_regs? This gets used later to take
APEI by the hand through NMI->IRQ context, depending on what we
interrupted.
Changes since v6:
* Moved the voice of the commit message.
* moved arch_local_save_flags() below the !IS_ENABLED drop-out
* Moved the dummy declaration into the if-ACPI part of the header instead
of if-APEI.
Changes since v4:
* Made irqs-unmasked comment a lockdep assert.
Changes since v3:
* Removed spurious whitespace change
* Updated comment in acpi.c to cover SError masking
Changes since v2:
* Added dummy definition for !ACPI and culled IS_ENABLED() checks.
---
arch/arm64/include/asm/acpi.h | 4 +++-
arch/arm64/include/asm/daifflags.h | 1 +
arch/arm64/include/asm/kvm_ras.h | 16 ++++++++++++++-
arch/arm64/kernel/acpi.c | 31 ++++++++++++++++++++++++++++++
arch/arm64/mm/fault.c | 24 +++++------------------
5 files changed, 55 insertions(+), 21 deletions(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 2def77ec14be..7628efbe6c12 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -18,6 +18,7 @@
#include <asm/cputype.h>
#include <asm/io.h>
+#include <asm/ptrace.h>
#include <asm/smp_plat.h>
#include <asm/tlbflush.h>
@@ -110,9 +111,10 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
static inline void arch_fix_phys_package_id(int num, u32 slot) { }
void __init acpi_init_cpus(void);
-
+int apei_claim_sea(struct pt_regs *regs);
#else
static inline void acpi_init_cpus(void) { }
+static inline int apei_claim_sea(struct pt_regs *regs) { return -ENOENT; }
#endif /* CONFIG_ACPI */
#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h
index 8d91f2233135..fa90779fc752 100644
--- a/arch/arm64/include/asm/daifflags.h
+++ b/arch/arm64/include/asm/daifflags.h
@@ -20,6 +20,7 @@
#define DAIF_PROCCTX 0
#define DAIF_PROCCTX_NOIRQ PSR_I_BIT
+#define DAIF_ERRCTX (PSR_I_BIT | PSR_A_BIT)
/* mask/save/unmask/restore all exceptions, including interrupts. */
static inline void local_daif_mask(void)
diff --git a/arch/arm64/include/asm/kvm_ras.h b/arch/arm64/include/asm/kvm_ras.h
index 6096f0251812..8ac6ee77437c 100644
--- a/arch/arm64/include/asm/kvm_ras.h
+++ b/arch/arm64/include/asm/kvm_ras.h
@@ -4,8 +4,22 @@
#ifndef __ARM64_KVM_RAS_H__
#define __ARM64_KVM_RAS_H__
+#include <linux/acpi.h>
+#include <linux/errno.h>
#include <linux/types.h>
-int kvm_handle_guest_sea(phys_addr_t addr, unsigned int esr);
+#include <asm/acpi.h>
+
+/*
+ * Was this synchronous external abort a RAS notification?
+ * Returns '0' for errors handled by some RAS subsystem, or -ENOENT.
+ */
+static inline int kvm_handle_guest_sea(phys_addr_t addr, unsigned int esr)
+{
+ /* apei_claim_sea(NULL) expects to mask interrupts itself */
+ lockdep_assert_irqs_enabled();
+
+ return apei_claim_sea(NULL);
+}
#endif /* __ARM64_KVM_RAS_H__ */
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 44e3c351e1ea..803f0494dd3e 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -27,8 +27,10 @@
#include <linux/smp.h>
#include <linux/serial_core.h>
+#include <acpi/ghes.h>
#include <asm/cputype.h>
#include <asm/cpu_ops.h>
+#include <asm/daifflags.h>
#include <asm/pgtable.h>
#include <asm/smp_plat.h>
@@ -256,3 +258,32 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
return __pgprot(PROT_NORMAL_NC);
return __pgprot(PROT_DEVICE_nGnRnE);
}
+
+/*
+ * Claim Synchronous External Aborts as a firmware first notification.
+ *
+ * Used by KVM and the arch do_sea handler.
+ * @regs may be NULL when called from process context.
+ */
+int apei_claim_sea(struct pt_regs *regs)
+{
+ int err = -ENOENT;
+ unsigned long current_flags;
+
+ if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
+ return err;
+
+ current_flags = arch_local_save_flags();
+
+ /*
+ * SEA can interrupt SError, mask it and describe this as an NMI so
+ * that APEI defers the handling.
+ */
+ local_daif_restore(DAIF_ERRCTX);
+ nmi_enter();
+ err = ghes_notify_sea();
+ nmi_exit();
+ local_daif_restore(current_flags);
+
+ return err;
+}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index c76dc981e3fc..e1c84c2e1cab 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -18,6 +18,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/acpi.h>
#include <linux/extable.h>
#include <linux/signal.h>
#include <linux/mm.h>
@@ -33,6 +34,7 @@
#include <linux/preempt.h>
#include <linux/hugetlb.h>
+#include <asm/acpi.h>
#include <asm/bug.h>
#include <asm/cmpxchg.h>
#include <asm/cpufeature.h>
@@ -47,8 +49,6 @@
#include <asm/tlbflush.h>
#include <asm/traps.h>
-#include <acpi/ghes.h>
-
struct fault_info {
int (*fn)(unsigned long addr, unsigned int esr,
struct pt_regs *regs);
@@ -643,19 +643,10 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
inf = esr_to_fault_info(esr);
/*
- * Synchronous aborts may interrupt code which had interrupts masked.
- * Before calling out into the wider kernel tell the interested
- * subsystems.
+ * Return value ignored as we rely on signal merging.
+ * Future patches will make this more robust.
*/
- if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
- if (interrupts_enabled(regs))
- nmi_enter();
-
- ghes_notify_sea();
-
- if (interrupts_enabled(regs))
- nmi_exit();
- }
+ apei_claim_sea(regs);
if (esr & ESR_ELx_FnV)
siaddr = NULL;
@@ -733,11 +724,6 @@ static const struct fault_info fault_info[] = {
{ do_bad, SIGKILL, SI_KERNEL, "unknown 63" },
};
-int kvm_handle_guest_sea(phys_addr_t addr, unsigned int esr)
-{
- return ghes_notify_sea();
-}
-
asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
--
2.20.1
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next prev parent reply other threads:[~2019-01-29 18:54 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-29 18:48 [PATCH v8 00/26] APEI in_nmi() rework and SDEI wire-up James Morse
2019-01-29 18:48 ` [PATCH v8 01/26] ACPI / APEI: Don't wait to serialise with oops messages when panic()ing James Morse
2019-01-29 18:48 ` [PATCH v8 02/26] ACPI / APEI: Remove silent flag from ghes_read_estatus() James Morse
2019-01-29 18:48 ` [PATCH v8 03/26] ACPI / APEI: Switch estatus pool to use vmalloc memory James Morse
2019-01-29 18:48 ` [PATCH v8 04/26] ACPI / APEI: Make hest.c manage the estatus memory pool James Morse
2019-02-01 13:20 ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 05/26] ACPI / APEI: Make estatus pool allocation a static size James Morse
2019-01-29 18:48 ` [PATCH v8 06/26] ACPI / APEI: Don't store CPER records physical address in struct ghes James Morse
2019-01-29 18:48 ` [PATCH v8 07/26] ACPI / APEI: Remove spurious GHES_TO_CLEAR check James Morse
2019-01-29 18:48 ` [PATCH v8 08/26] ACPI / APEI: Don't update struct ghes' flags in read/clear estatus James Morse
2019-01-29 18:48 ` [PATCH v8 09/26] ACPI / APEI: Generalise the estatus queue's notify code James Morse
2019-02-01 13:46 ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 10/26] ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors James Morse
2019-01-29 18:48 ` [PATCH v8 11/26] ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI James Morse
2019-01-29 18:48 ` [PATCH v8 12/26] ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue James Morse
2019-01-29 18:48 ` [PATCH v8 13/26] KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing James Morse
2019-01-29 18:48 ` James Morse [this message]
2019-01-29 18:48 ` [PATCH v8 15/26] ACPI / APEI: Move locking to the notification helper James Morse
2019-01-29 18:48 ` [PATCH v8 16/26] ACPI / APEI: Let the notification helper specify the fixmap slot James Morse
2019-01-29 18:48 ` [PATCH v8 17/26] ACPI / APEI: Pass ghes and estatus separately to avoid a later copy James Morse
2019-01-29 18:48 ` [PATCH v8 18/26] ACPI / APEI: Make GHES estatus header validation more user friendly James Morse
2019-02-01 14:30 ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 19/26] ACPI / APEI: Split ghes_read_estatus() to allow a peek at the CPER length James Morse
2019-01-29 18:48 ` [PATCH v8 20/26] ACPI / APEI: Only use queued estatus entry during in_nmi_queue_one_entry() James Morse
2019-01-29 18:48 ` [PATCH v8 21/26] ACPI / APEI: Use separate fixmap pages for arm64 NMI-like notifications James Morse
2019-01-29 18:48 ` [PATCH v8 22/26] mm/memory-failure: Add memory_failure_queue_kick() James Morse
2019-01-29 18:48 ` [PATCH v8 23/26] ACPI / APEI: Kick the memory_failure() queue for synchronous errors James Morse
2019-01-29 18:49 ` [PATCH v8 24/26] arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work James Morse
2019-01-30 8:56 ` Julien Thierry
2019-01-29 18:49 ` [PATCH v8 25/26] firmware: arm_sdei: Add ACPI GHES registration helper James Morse
2019-01-29 18:49 ` [PATCH v8 26/26] ACPI / APEI: Add support for the SDEI GHES Notification type James Morse
2019-02-08 11:40 ` [PATCH v8 00/26] APEI in_nmi() rework and SDEI wire-up Rafael J. Wysocki
2019-02-08 14:13 ` James Morse
2019-02-11 11:05 ` Rafael J. Wysocki
2019-02-11 18:35 ` James Morse
2019-02-12 22:14 ` Rafael J. Wysocki
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