Commit 5870970b authored by Julien Thierry's avatar Julien Thierry Committed by Catalin Marinas
Browse files

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: default avatarJulien Thierry <julien.thierry@arm.com>
Suggested-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: default avatarJames 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: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent e26a4331

arch/arm64/include/asm/hardirq.h

+31 −0
Original line number Diff line number Diff line
@@ -17,8 +17,12 @@ 
#define __ASM_HARDIRQ_H



#include <linux/cache.h>

#include <linux/percpu.h>

#include <linux/threads.h>

#include <asm/barrier.h>

#include <asm/irq.h>

#include <asm/kvm_arm.h>

#include <asm/sysreg.h>



#define NR_IPI	7
@@ -37,6 +41,33 @@ u64 smp_irq_stat_cpu(unsigned int cpu); 


#define __ARCH_IRQ_EXIT_IRQS_DISABLED	1



struct nmi_ctx {

	u64 hcr;

};



DECLARE_PER_CPU(struct nmi_ctx, nmi_contexts);



#define arch_nmi_enter()							\

	do {									\

		if (is_kernel_in_hyp_mode()) {					\

			struct nmi_ctx *nmi_ctx = this_cpu_ptr(&nmi_contexts);	\

			nmi_ctx->hcr = read_sysreg(hcr_el2);			\

			if (!(nmi_ctx->hcr & HCR_TGE)) {			\

				write_sysreg(nmi_ctx->hcr | HCR_TGE, hcr_el2);	\

				isb();						\

			}							\

		}								\

	} while (0)



#define arch_nmi_exit()								\

	do {									\

		if (is_kernel_in_hyp_mode()) {					\

			struct nmi_ctx *nmi_ctx = this_cpu_ptr(&nmi_contexts);	\

			if (!(nmi_ctx->hcr & HCR_TGE))				\

				write_sysreg(nmi_ctx->hcr, hcr_el2);		\

		}								\

	} while (0)



static inline void ack_bad_irq(unsigned int irq)

{

	extern unsigned long irq_err_count;

arch/arm64/kernel/irq.c

+3 −0
Original line number Diff line number Diff line
@@ -33,6 +33,9 @@ 


unsigned long irq_err_count;



/* Only access this in an NMI enter/exit */

DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);



DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);



int arch_show_interrupts(struct seq_file *p, int prec)

include/linux/hardirq.h

+7 −0
Original line number Diff line number Diff line
@@ -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 */

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