arm64: Fix HCR.TGE status for NMI contexts

When using VHE, the host needs to clear HCR_EL2.TGE bit in order
to interact with guest TLBs, switching from EL2&0 translation regime
to EL1&0.

However, some non-maskable asynchronous event could happen while TGE is
cleared like SDEI. Because of this address translation operations
relying on EL2&0 translation regime could fail (tlb invalidation,
userspace access, ...).

Fix this by properly setting HCR_EL2.TGE when entering NMI context and
clear it if necessary when returning to the interrupted context.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 0fbbcdf0c178..da0af631ded5 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -60,8 +60,14 @@ extern void irq_enter(void);
  */
 extern void irq_exit(void);
 
+#ifndef arch_nmi_enter
+#define arch_nmi_enter()        do { } while (0)
+#define arch_nmi_exit()         do { } while (0)
+#endif
+
 #define nmi_enter()                                             \
         do {                                                    \
+                arch_nmi_enter();                               \
                 printk_nmi_enter();                             \
                 lockdep_off();                                  \
                 ftrace_nmi_enter();                             \
@@ -80,6 +86,7 @@ extern void irq_exit(void);
                 ftrace_nmi_exit();                              \
                 lockdep_on();                                   \
                 printk_nmi_exit();                              \
+                arch_nmi_exit();                                \
         } while (0)
 
 #endif /* LINUX_HARDIRQ_H */