From: Marc Zyngier <marc.zyngier@xxxxxxx> [ Upstream commit c987876a80e7bcb98a839f10dca9ce7fda4feced ] 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@xxxxxxxxxxxxxxx Acked-by: Christoffer Dall <christoffer.dall@xxxxxxx> Reviewed-by: James Morse <james.morse@xxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- arch/arm64/kvm/hyp/tlb.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c index 73464a96c365..db23c6e5c885 100644 --- a/arch/arm64/kvm/hyp/tlb.c +++ b/arch/arm64/kvm/hyp/tlb.c @@ -15,13 +15,18 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/irqflags.h> + #include <asm/kvm_hyp.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 @@ -36,7 +41,8 @@ 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) { write_sysreg(kvm->arch.vttbr, vttbr_el2); isb(); @@ -47,7 +53,8 @@ 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 @@ -55,9 +62,12 @@ 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); } @@ -69,11 +79,13 @@ 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. @@ -116,36 +128,39 @@ 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) -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
