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Commit c773ae2b authored by James Morse's avatar James Morse Committed by Catalin Marinas
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KVM: arm64: Save/Restore guest DISR_EL1 



If we deliver a virtual SError to the guest, the guest may defer it
with an ESB instruction. The guest reads the deferred value via DISR_EL1,
but the guests view of DISR_EL1 is re-mapped to VDISR_EL2 when HCR_EL2.AMO
is set.

Add the KVM code to save/restore VDISR_EL2, and make it accessible to
userspace as DISR_EL1.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 4715c14b

arch/arm64/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -121,6 +121,7 @@ enum vcpu_sysreg { 
	PAR_EL1,	/* Physical Address Register */

	MDSCR_EL1,	/* Monitor Debug System Control Register */

	MDCCINT_EL1,	/* Monitor Debug Comms Channel Interrupt Enable Reg */

	DISR_EL1,	/* Deferred Interrupt Status Register */



	/* Performance Monitors Registers */

	PMCR_EL0,	/* Control Register */

arch/arm64/include/asm/sysreg.h

+1 −0
Original line number Diff line number Diff line
@@ -358,6 +358,7 @@ 
#define SYS_VSESR_EL2			sys_reg(3, 4, 5, 2, 3)

#define SYS_FPEXC32_EL2			sys_reg(3, 4, 5, 3, 0)



#define SYS_VDISR_EL2			sys_reg(3, 4, 12, 1,  1)

#define __SYS__AP0Rx_EL2(x)		sys_reg(3, 4, 12, 8, x)

#define SYS_ICH_AP0R0_EL2		__SYS__AP0Rx_EL2(0)

#define SYS_ICH_AP0R1_EL2		__SYS__AP0Rx_EL2(1)

arch/arm64/kvm/hyp/sysreg-sr.c

+6 −0
Original line number Diff line number Diff line
@@ -66,6 +66,9 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) 
	ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);

	ctxt->gp_regs.regs.pc		= read_sysreg_el2(elr);

	ctxt->gp_regs.regs.pstate	= read_sysreg_el2(spsr);



	if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))

		ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2);

}



static hyp_alternate_select(__sysreg_call_save_host_state,
@@ -119,6 +122,9 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt) 
	write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);

	write_sysreg_el2(ctxt->gp_regs.regs.pc,		elr);

	write_sysreg_el2(ctxt->gp_regs.regs.pstate,	spsr);



	if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))

		write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2);

}



static hyp_alternate_select(__sysreg_call_restore_host_state,

arch/arm64/kvm/sys_regs.c

+1 −0
Original line number Diff line number Diff line
@@ -1169,6 +1169,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { 
	{ SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },



	{ SYS_DESC(SYS_VBAR_EL1), NULL, reset_val, VBAR_EL1, 0 },

	{ SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },



	{ SYS_DESC(SYS_ICC_IAR0_EL1), write_to_read_only },

	{ SYS_DESC(SYS_ICC_EOIR0_EL1), read_from_write_only },