KVM: arm64: Handle host stage-2 faults from 32-bit EL0
Will Deacon
maintainerPATCH 1/1 KVM: arm64: Handle host stage-2 faults from 32-bit EL0
When pKVM is enabled, host memory accesses are translated by an identity mapping at stage-2, which is populated lazily in response to synchronous exceptions from 64-bit EL1 and EL0.
Extend this handling to cover exceptions originating from 32-bit EL0 as well. Although these are very unlikely to occur in practice, as the kernel typically ensures that user pages are initialised before mapping them in, drivers could still map previously untouched device pages into userspace and expect things to work rather than panic the system.
--- arch/arm64/kvm/hyp/nvhe/host.S | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
arch/arm64/kvm/hyp/nvhe/host.S +9 -9
@@ -198,15 +198,15 @@ SYM_CODE_START(__kvm_hyp_host_vector) invalid_host_el2_vect // FIQ EL2h invalid_host_el2_vect // Error EL2h - host_el1_sync_vect // Synchronous 64-bit EL1 - invalid_host_el1_vect // IRQ 64-bit EL1 - invalid_host_el1_vect // FIQ 64-bit EL1 - invalid_host_el1_vect // Error 64-bit EL1 - - invalid_host_el1_vect // Synchronous 32-bit EL1 - invalid_host_el1_vect // IRQ 32-bit EL1 - invalid_host_el1_vect // FIQ 32-bit EL1 - invalid_host_el1_vect // Error 32-bit EL1 + host_el1_sync_vect // Synchronous 64-bit EL1/EL0 + invalid_host_el1_vect // IRQ 64-bit EL1/EL0 + invalid_host_el1_vect // FIQ 64-bit EL1/EL0 + invalid_host_el1_vect // Error 64-bit EL1/EL0 + + host_el1_sync_vect // Synchronous 32-bit EL1/EL0 + invalid_host_el1_vect // IRQ 32-bit EL1/EL0 + invalid_host_el1_vect // FIQ 32-bit EL1/EL0 + invalid_host_el1_vect // Error 32-bit EL1/EL0 SYM_CODE_END(__kvm_hyp_host_vector) /*
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Quoted 9 lines · Will Deacon
When pKVM is enabled, host memory accesses are translated by an identity mapping at stage-2, which is populated lazily in response to synchronous exceptions from 64-bit EL1 and EL0.
Extend this handling to cover exceptions originating from 32-bit EL0 as well. Although these are very unlikely to occur in practice, as the kernel typically ensures that user pages are initialised before mapping them in, drivers could still map previously untouched device pages into userspace and expect things to work rather than panic the system.
Applied to fixes, thanks!
[1/1] KVM: arm64: Handle host stage-2 faults from 32-bit EL0
commit: 2a50fc5fd09798cc154b587acd4f4ee261ea19be
Cheers,
M.
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