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Commit 060701f0 authored by Christoffer Dall's avatar Christoffer Dall Committed by Marc Zyngier
Browse files

KVM: arm64: Move userspace system registers into separate function 



There's a semantic difference between the EL1 registers that control
operation of a kernel running in EL1 and EL1 registers that only control
userspace execution in EL0.  Since we can defer saving/restoring the
latter, move them into their own function.

The ARMv8 ARM (ARM DDI 0487C.a) Section D10.2.1 recommends that
ACTLR_EL1 has no effect on the processor when running the VHE host, and
we can therefore move this register into the EL1 state which is only
saved/restored on vcpu_put/load for a VHE host.

We also take this chance to rename the function saving/restoring the
remaining system register to make it clear this function deals with
the EL1 system registers.

Reviewed-by: default avatarAndrew Jones <drjones@redhat.com>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 04fef057

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

+35 −13
Original line number Diff line number Diff line
@@ -28,24 +28,33 @@ static void __hyp_text __sysreg_do_nothing(struct kvm_cpu_context *ctxt) { } 
/*

 * Non-VHE: Both host and guest must save everything.

 *

 * VHE: Host must save tpidr*_el0, actlr_el1, mdscr_el1, sp_el0,

 * VHE: Host must save tpidr*_el0, mdscr_el1, sp_el0,

 * and guest must save everything.

 */



static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)

{

	ctxt->sys_regs[ACTLR_EL1]	= read_sysreg(actlr_el1);

	ctxt->sys_regs[TPIDR_EL0]	= read_sysreg(tpidr_el0);

	ctxt->sys_regs[TPIDRRO_EL0]	= read_sysreg(tpidrro_el0);

	ctxt->sys_regs[MDSCR_EL1]	= read_sysreg(mdscr_el1);



	/*

	 * The host arm64 Linux uses sp_el0 to point to 'current' and it must

	 * therefore be saved/restored on every entry/exit to/from the guest.

	 */

	ctxt->gp_regs.regs.sp		= read_sysreg(sp_el0);

}



static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)

static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)

{

	ctxt->sys_regs[TPIDR_EL0]	= read_sysreg(tpidr_el0);

	ctxt->sys_regs[TPIDRRO_EL0]	= read_sysreg(tpidrro_el0);

}



static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)

{

	ctxt->sys_regs[MPIDR_EL1]	= read_sysreg(vmpidr_el2);

	ctxt->sys_regs[CSSELR_EL1]	= read_sysreg(csselr_el1);

	ctxt->sys_regs[SCTLR_EL1]	= read_sysreg_el1(sctlr);

	ctxt->sys_regs[ACTLR_EL1]	= read_sysreg(actlr_el1);

	ctxt->sys_regs[CPACR_EL1]	= read_sysreg_el1(cpacr);

	ctxt->sys_regs[TTBR0_EL1]	= read_sysreg_el1(ttbr0);

	ctxt->sys_regs[TTBR1_EL1]	= read_sysreg_el1(ttbr1);
@@ -73,35 +82,46 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) 
}



static hyp_alternate_select(__sysreg_call_save_host_state,

			    __sysreg_save_state, __sysreg_do_nothing,

			    __sysreg_save_el1_state, __sysreg_do_nothing,

			    ARM64_HAS_VIRT_HOST_EXTN);



void __hyp_text __sysreg_save_host_state(struct kvm_cpu_context *ctxt)

{

	__sysreg_call_save_host_state()(ctxt);

	__sysreg_save_common_state(ctxt);

	__sysreg_save_user_state(ctxt);

}



void __hyp_text __sysreg_save_guest_state(struct kvm_cpu_context *ctxt)

{

	__sysreg_save_state(ctxt);

	__sysreg_save_el1_state(ctxt);

	__sysreg_save_common_state(ctxt);

	__sysreg_save_user_state(ctxt);

}



static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)

{

	write_sysreg(ctxt->sys_regs[ACTLR_EL1],	  actlr_el1);

	write_sysreg(ctxt->sys_regs[TPIDR_EL0],	  tpidr_el0);

	write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);

	write_sysreg(ctxt->sys_regs[MDSCR_EL1],	  mdscr_el1);



	/*

	 * The host arm64 Linux uses sp_el0 to point to 'current' and it must

	 * therefore be saved/restored on every entry/exit to/from the guest.

	 */

	write_sysreg(ctxt->gp_regs.regs.sp,	  sp_el0);

}



static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)

static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)

{

	write_sysreg(ctxt->sys_regs[TPIDR_EL0],	  	tpidr_el0);

	write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], 	tpidrro_el0);

}



static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)

{

	write_sysreg(ctxt->sys_regs[MPIDR_EL1],		vmpidr_el2);

	write_sysreg(ctxt->sys_regs[CSSELR_EL1],	csselr_el1);

	write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1],	sctlr);

	write_sysreg(ctxt->sys_regs[ACTLR_EL1],	  	actlr_el1);

	write_sysreg_el1(ctxt->sys_regs[CPACR_EL1],	cpacr);

	write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1],	ttbr0);

	write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1],	ttbr1);
@@ -129,19 +149,21 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt) 
}



static hyp_alternate_select(__sysreg_call_restore_host_state,

			    __sysreg_restore_state, __sysreg_do_nothing,

			    __sysreg_restore_el1_state, __sysreg_do_nothing,

			    ARM64_HAS_VIRT_HOST_EXTN);



void __hyp_text __sysreg_restore_host_state(struct kvm_cpu_context *ctxt)

{

	__sysreg_call_restore_host_state()(ctxt);

	__sysreg_restore_common_state(ctxt);

	__sysreg_restore_user_state(ctxt);

}



void __hyp_text __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt)

{

	__sysreg_restore_state(ctxt);

	__sysreg_restore_el1_state(ctxt);

	__sysreg_restore_common_state(ctxt);

	__sysreg_restore_user_state(ctxt);

}



void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)