4.20-stable review patch. If anyone has any objections, please let me know.
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From: Marc Zyngier marc.zyngier@arm.com
commit c987876a80e7bcb98a839f10dca9ce7fda4feced upstream.
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: Christoffer Dall christoffer.dall@arm.com Reviewed-by: James Morse james.morse@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/kvm/hyp/tlb.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-)
--- a/arch/arm64/kvm/hyp/tlb.c +++ b/arch/arm64/kvm/hyp/tlb.c @@ -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_g 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 __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_h */ 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
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 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)