Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1f742679 authored by James Morse's avatar James Morse Committed by Catalin Marinas
Browse files

KVM: arm64: Stop save/restoring host tpidr_el1 on VHE 



Now that a VHE host uses tpidr_el2 for the cpu offset we no longer
need KVM to save/restore tpidr_el1. Move this from the 'common' code
into the non-vhe code. While we're at it, on VHE we don't need to
save the ELR or SPSR as kernel_entry in entry.S will have pushed these
onto the kernel stack, and will restore them from there. Move these
to the non-vhe code as we need them to get back to the host.

Finally remove the always-copy-tpidr we hid in the stage2 setup
code, cpufeature's enable callback will do this for VHE, we only
need KVM to do it for non-vhe. Add the copy into kvm-init instead.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 6d99b689

arch/arm64/kvm/hyp-init.S

+4 −0
Original line number Diff line number Diff line
@@ -120,6 +120,10 @@ CPU_BE( orr x4, x4, #SCTLR_ELx_EE) 
	kern_hyp_va	x2

	msr	vbar_el2, x2



	/* copy tpidr_el1 into tpidr_el2 for use by HYP */

	mrs	x1, tpidr_el1

	msr	tpidr_el2, x1



	/* Hello, World! */

	eret

ENDPROC(__kvm_hyp_init)

arch/arm64/kvm/hyp/s2-setup.c

+0 −3
Original line number Diff line number Diff line
@@ -86,8 +86,5 @@ u32 __hyp_text __init_stage2_translation(void) 


	write_sysreg(val, vtcr_el2);



	/* copy tpidr_el1 into tpidr_el2 for use by HYP */

	write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);



	return parange;

}

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

+8 −8
Original line number Diff line number Diff line
@@ -27,8 +27,8 @@ 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*_el[01], actlr_el1, mdscr_el1, sp0, pc,

 * pstate, and guest must save everything.

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

 * and guest must save everything.

 */



static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
@@ -36,11 +36,8 @@ 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[TPIDR_EL1]	= read_sysreg(tpidr_el1);

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

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

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

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

}



static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
@@ -62,10 +59,13 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) 
	ctxt->sys_regs[AMAIR_EL1]	= read_sysreg_el1(amair);

	ctxt->sys_regs[CNTKCTL_EL1]	= read_sysreg_el1(cntkctl);

	ctxt->sys_regs[PAR_EL1]		= read_sysreg(par_el1);

	ctxt->sys_regs[TPIDR_EL1]	= read_sysreg(tpidr_el1);



	ctxt->gp_regs.sp_el1		= read_sysreg(sp_el1);

	ctxt->gp_regs.elr_el1		= read_sysreg_el1(elr);

	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);

}



static hyp_alternate_select(__sysreg_call_save_host_state,
@@ -89,11 +89,8 @@ static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctx 
	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[TPIDR_EL1],	  tpidr_el1);

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

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

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

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

}



static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
@@ -115,10 +112,13 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt) 
	write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1],	amair);

	write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], 	cntkctl);

	write_sysreg(ctxt->sys_regs[PAR_EL1],		par_el1);

	write_sysreg(ctxt->sys_regs[TPIDR_EL1],		tpidr_el1);



	write_sysreg(ctxt->gp_regs.sp_el1,		sp_el1);

	write_sysreg_el1(ctxt->gp_regs.elr_el1,		elr);

	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);

}



static hyp_alternate_select(__sysreg_call_restore_host_state,