Commit 1e4448c5 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: KVM: Add synchronization on translation regime change for erratum 1165522 



In order to ensure that slipping HCR_EL2.TGE is done at the right
time when switching translation regime, let insert the required ISBs
that will be patched in when erratum 1165522 is detected.

Take this opportunity to add the missing include of asm/alternative.h
which was getting there by pure luck.

Acked-by: default avatarChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 8b2cca9a

arch/arm64/include/asm/kvm_hyp.h

+8 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 


#include <linux/compiler.h>

#include <linux/kvm_host.h>

#include <asm/alternative.h>

#include <asm/sysreg.h>



#define __hyp_text __section(.hyp.text) notrace
@@ -163,6 +164,13 @@ static __always_inline void __hyp_text __load_guest_stage2(struct kvm *kvm) 
{

	write_sysreg(kvm->arch.vtcr, vtcr_el2);

	write_sysreg(kvm->arch.vttbr, vttbr_el2);



	/*

	 * ARM erratum 1165522 requires the actual execution of the above

	 * before we can switch to the EL1/EL0 translation regime used by

	 * the guest.

	 */

	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522));

}



#endif /* __ARM64_KVM_HYP_H__ */

arch/arm64/kvm/hyp/switch.c

+19 −0
Original line number Diff line number Diff line
@@ -143,6 +143,14 @@ static void deactivate_traps_vhe(void) 
{

	extern char vectors[];	/* kernel exception vectors */

	write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);



	/*

	 * ARM erratum 1165522 requires the actual execution of the above

	 * before we can switch to the EL2/EL0 translation regime used by

	 * the host.

	 */

	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522));



	write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1);

	write_sysreg(vectors, vbar_el1);

}
@@ -499,6 +507,17 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) 


	sysreg_save_host_state_vhe(host_ctxt);



	/*

	 * ARM erratum 1165522 requires us to configure both stage 1 and

	 * stage 2 translation for the guest context before we clear

	 * HCR_EL2.TGE.

	 *

	 * We have already configured the guest's stage 1 translation in

	 * kvm_vcpu_load_sysregs above.  We must now call __activate_vm

	 * before __activate_traps, because __activate_vm configures

	 * stage 2 translation, and __activate_traps clear HCR_EL2.TGE

	 * (among other things).

	 */

	__activate_vm(vcpu->kvm);

	__activate_traps(vcpu);

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