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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: Tomasz Nowicki <tnowicki@caviumnetworks.com>
Tested-by: Tomasz Nowicki <tnowicki@caviumnetworks.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Marc Zyngier 2017-02-17 14:32:18 +00:00
parent c1ae3cfa0e
commit 6892517629
1 changed files with 55 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
arch/arm64/kvm/hyp/tlb.c
View File

@ -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)