Commit c987876a authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: KVM: Make VHE Stage-2 TLB invalidation operations non-interruptible 



Contrary to the non-VHE version of the TLB invalidation helpers, the VHE
code  has interrupts enabled, meaning that we can take an interrupt in
the middle of such a sequence, and start running something else with
HCR_EL2.TGE cleared.

That's really not a good idea.

Take the heavy-handed option and disable interrupts in
__tlb_switch_to_guest_vhe, restoring them in __tlb_switch_to_host_vhe.
The latter also gain an ISB in order to make sure that TGE really has
taken effect.

Cc: stable@vger.kernel.org
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 9ff01193

arch/arm64/kvm/hyp/tlb.c

+25 −10
Original line number Diff line number Diff line
@@ -15,14 +15,19 @@ 
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#include <linux/irqflags.h>



#include <asm/kvm_hyp.h>

#include <asm/kvm_mmu.h>

#include <asm/tlbflush.h>



static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)

static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,

						 unsigned long *flags)

{

	u64 val;



	local_irq_save(*flags);



	/*

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

	 * most TLB operations target EL2/EL0. In order to affect the
@@ -37,7 +42,8 @@ static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm) 
	isb();

}



static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm)

static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm,

						  unsigned long *flags)

{

	__load_guest_stage2(kvm);

	isb();
@@ -48,7 +54,8 @@ static hyp_alternate_select(__tlb_switch_to_guest, 
			    __tlb_switch_to_guest_vhe,

			    ARM64_HAS_VIRT_HOST_EXTN);



static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm)

static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm,

						unsigned long flags)

{

	/*

	 * We're done with the TLB operation, let's restore the host's
@@ -56,9 +63,12 @@ static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm) 
	 */

	write_sysreg(0, vttbr_el2);

	write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);

	isb();

	local_irq_restore(flags);

}



static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm)

static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm,

						 unsigned long flags)

{

	write_sysreg(0, vttbr_el2);

}
@@ -70,11 +80,13 @@ static hyp_alternate_select(__tlb_switch_to_host, 


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

{

	unsigned long flags;



	dsb(ishst);



	/* Switch to requested VMID */

	kvm = kern_hyp_va(kvm);

	__tlb_switch_to_guest()(kvm);

	__tlb_switch_to_guest()(kvm, &flags);



	/*

	 * We could do so much better if we had the VA as well.
@@ -117,36 +129,39 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) 
	if (!has_vhe() && icache_is_vpipt())

		__flush_icache_all();



	__tlb_switch_to_host()(kvm);

	__tlb_switch_to_host()(kvm, flags);

}



void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)

{

	unsigned long flags;



	dsb(ishst);



	/* Switch to requested VMID */

	kvm = kern_hyp_va(kvm);

	__tlb_switch_to_guest()(kvm);

	__tlb_switch_to_guest()(kvm, &flags);



	__tlbi(vmalls12e1is);

	dsb(ish);

	isb();



	__tlb_switch_to_host()(kvm);

	__tlb_switch_to_host()(kvm, flags);

}



void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)

{

	struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);

	unsigned long flags;



	/* Switch to requested VMID */

	__tlb_switch_to_guest()(kvm);

	__tlb_switch_to_guest()(kvm, &flags);



	__tlbi(vmalle1);

	dsb(nsh);

	isb();



	__tlb_switch_to_host()(kvm);

	__tlb_switch_to_host()(kvm, flags);

}



void __hyp_text __kvm_flush_vm_context(void)

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