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Commit 68925176 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

arm64: KVM: VHE: Clear HCR_TGE when invalidating guest TLBs 



When invalidating guest TLBs, special care must be taken to
actually shoot the guest TLBs and not the host ones if we're
running on a VHE system.  This is controlled by the HCR_EL2.TGE
bit, which we forget to clear before invalidating TLBs.

Address the issue by introducing two wrappers (__tlb_switch_to_guest
and __tlb_switch_to_host) that take care of both the VTTBR_EL2
and HCR_EL2.TGE switching.

Reported-by: default avatarTomasz Nowicki <tnowicki@caviumnetworks.com>
Tested-by: default avatarTomasz Nowicki <tnowicki@caviumnetworks.com>
Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent c1ae3cfa

arch/arm64/kvm/hyp/tlb.c

+55 −9
Original line number Diff line number Diff line
@@ -18,14 +18,62 @@ 
#include <asm/kvm_hyp.h>

#include <asm/tlbflush.h>



static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)

{

	u64 val;



	/*

	 * With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and

	 * most TLB operations target EL2/EL0. In order to affect the

	 * guest TLBs (EL1/EL0), we need to change one of these two

	 * bits. Changing E2H is impossible (goodbye TTBR1_EL2), so

	 * let's flip TGE before executing the TLB operation.

	 */

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

	val = read_sysreg(hcr_el2);

	val &= ~HCR_TGE;

	write_sysreg(val, hcr_el2);

	isb();

}



static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm)

{

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

	isb();

}



static hyp_alternate_select(__tlb_switch_to_guest,

			    __tlb_switch_to_guest_nvhe,

			    __tlb_switch_to_guest_vhe,

			    ARM64_HAS_VIRT_HOST_EXTN);



static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm)

{

	/*

	 * We're done with the TLB operation, let's restore the host's

	 * view of HCR_EL2.

	 */

	write_sysreg(0, vttbr_el2);

	write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);

}



static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm)

{

	write_sysreg(0, vttbr_el2);

}



static hyp_alternate_select(__tlb_switch_to_host,

			    __tlb_switch_to_host_nvhe,

			    __tlb_switch_to_host_vhe,

			    ARM64_HAS_VIRT_HOST_EXTN);



void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

{

	dsb(ishst);



	/* Switch to requested VMID */

	kvm = kern_hyp_va(kvm);

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

	isb();

	__tlb_switch_to_guest()(kvm);



	/*

	 * We could do so much better if we had the VA as well.
@@ -46,7 +94,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) 
	dsb(ish);

	isb();



	write_sysreg(0, vttbr_el2);

	__tlb_switch_to_host()(kvm);

}



void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
@@ -55,14 +103,13 @@ void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm) 


	/* Switch to requested VMID */

	kvm = kern_hyp_va(kvm);

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

	isb();

	__tlb_switch_to_guest()(kvm);



	__tlbi(vmalls12e1is);

	dsb(ish);

	isb();



	write_sysreg(0, vttbr_el2);

	__tlb_switch_to_host()(kvm);

}



void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
@@ -70,14 +117,13 @@ void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu) 
	struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);



	/* Switch to requested VMID */

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

	isb();

	__tlb_switch_to_guest()(kvm);



	__tlbi(vmalle1);

	dsb(nsh);

	isb();



	write_sysreg(0, vttbr_el2);

	__tlb_switch_to_host()(kvm);

}



void __hyp_text __kvm_flush_vm_context(void)