Searched hist:"7 d894834" (Results 1 – 3 of 3) sorted by relevance
/openbmc/linux/arch/arm64/include/asm/ |
H A D | esr.h | 7d894834 Tue Dec 01 14:10:34 CST 2020 Yanan Wang <wangyanan55@huawei.com> KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort()
If we get a FSC_PERM fault, just using (logging_active && writable) to determine calling kvm_pgtable_stage2_map(). There will be two more cases we should consider.
(1) After logging_active is configged back to false from true. When we get a FSC_PERM fault with write_fault and adjustment of hugepage is needed, we should merge tables back to a block entry. This case is ignored by still calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless loop and guest panic due to soft lockup.
(2) We use (FSC_PERM && logging_active && writable) to determine collapsing a block entry into a table by calling kvm_pgtable_stage2_map(). But sometimes we may only need to relax permissions when trying to write to a page other than a block. In this condition,using kvm_pgtable_stage2_relax_perms() will be fine.
The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup level at which a D-abort or I-abort occurred. By comparing granule of the fault lookup level with vma_pagesize, we can strictly distinguish conditions of calling kvm_pgtable_stage2_relax_perms() or kvm_pgtable_stage2_map(), and the above two cases will be well considered.
Suggested-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201201201034.116760-4-wangyanan55@huawei.com 7d894834 Tue Dec 01 14:10:34 CST 2020 Yanan Wang <wangyanan55@huawei.com> KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort() If we get a FSC_PERM fault, just using (logging_active && writable) to determine calling kvm_pgtable_stage2_map(). There will be two more cases we should consider. (1) After logging_active is configged back to false from true. When we get a FSC_PERM fault with write_fault and adjustment of hugepage is needed, we should merge tables back to a block entry. This case is ignored by still calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless loop and guest panic due to soft lockup. (2) We use (FSC_PERM && logging_active && writable) to determine collapsing a block entry into a table by calling kvm_pgtable_stage2_map(). But sometimes we may only need to relax permissions when trying to write to a page other than a block. In this condition,using kvm_pgtable_stage2_relax_perms() will be fine. The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup level at which a D-abort or I-abort occurred. By comparing granule of the fault lookup level with vma_pagesize, we can strictly distinguish conditions of calling kvm_pgtable_stage2_relax_perms() or kvm_pgtable_stage2_map(), and the above two cases will be well considered. Suggested-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201201201034.116760-4-wangyanan55@huawei.com
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H A D | kvm_emulate.h | 7d894834 Tue Dec 01 14:10:34 CST 2020 Yanan Wang <wangyanan55@huawei.com> KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort()
If we get a FSC_PERM fault, just using (logging_active && writable) to determine calling kvm_pgtable_stage2_map(). There will be two more cases we should consider.
(1) After logging_active is configged back to false from true. When we get a FSC_PERM fault with write_fault and adjustment of hugepage is needed, we should merge tables back to a block entry. This case is ignored by still calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless loop and guest panic due to soft lockup.
(2) We use (FSC_PERM && logging_active && writable) to determine collapsing a block entry into a table by calling kvm_pgtable_stage2_map(). But sometimes we may only need to relax permissions when trying to write to a page other than a block. In this condition,using kvm_pgtable_stage2_relax_perms() will be fine.
The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup level at which a D-abort or I-abort occurred. By comparing granule of the fault lookup level with vma_pagesize, we can strictly distinguish conditions of calling kvm_pgtable_stage2_relax_perms() or kvm_pgtable_stage2_map(), and the above two cases will be well considered.
Suggested-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201201201034.116760-4-wangyanan55@huawei.com 7d894834 Tue Dec 01 14:10:34 CST 2020 Yanan Wang <wangyanan55@huawei.com> KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort() If we get a FSC_PERM fault, just using (logging_active && writable) to determine calling kvm_pgtable_stage2_map(). There will be two more cases we should consider. (1) After logging_active is configged back to false from true. When we get a FSC_PERM fault with write_fault and adjustment of hugepage is needed, we should merge tables back to a block entry. This case is ignored by still calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless loop and guest panic due to soft lockup. (2) We use (FSC_PERM && logging_active && writable) to determine collapsing a block entry into a table by calling kvm_pgtable_stage2_map(). But sometimes we may only need to relax permissions when trying to write to a page other than a block. In this condition,using kvm_pgtable_stage2_relax_perms() will be fine. The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup level at which a D-abort or I-abort occurred. By comparing granule of the fault lookup level with vma_pagesize, we can strictly distinguish conditions of calling kvm_pgtable_stage2_relax_perms() or kvm_pgtable_stage2_map(), and the above two cases will be well considered. Suggested-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201201201034.116760-4-wangyanan55@huawei.com
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/openbmc/linux/arch/arm64/kvm/ |
H A D | mmu.c | 7d894834 Tue Dec 01 14:10:34 CST 2020 Yanan Wang <wangyanan55@huawei.com> KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort()
If we get a FSC_PERM fault, just using (logging_active && writable) to determine calling kvm_pgtable_stage2_map(). There will be two more cases we should consider.
(1) After logging_active is configged back to false from true. When we get a FSC_PERM fault with write_fault and adjustment of hugepage is needed, we should merge tables back to a block entry. This case is ignored by still calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless loop and guest panic due to soft lockup.
(2) We use (FSC_PERM && logging_active && writable) to determine collapsing a block entry into a table by calling kvm_pgtable_stage2_map(). But sometimes we may only need to relax permissions when trying to write to a page other than a block. In this condition,using kvm_pgtable_stage2_relax_perms() will be fine.
The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup level at which a D-abort or I-abort occurred. By comparing granule of the fault lookup level with vma_pagesize, we can strictly distinguish conditions of calling kvm_pgtable_stage2_relax_perms() or kvm_pgtable_stage2_map(), and the above two cases will be well considered.
Suggested-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201201201034.116760-4-wangyanan55@huawei.com 7d894834 Tue Dec 01 14:10:34 CST 2020 Yanan Wang <wangyanan55@huawei.com> KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort() If we get a FSC_PERM fault, just using (logging_active && writable) to determine calling kvm_pgtable_stage2_map(). There will be two more cases we should consider. (1) After logging_active is configged back to false from true. When we get a FSC_PERM fault with write_fault and adjustment of hugepage is needed, we should merge tables back to a block entry. This case is ignored by still calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless loop and guest panic due to soft lockup. (2) We use (FSC_PERM && logging_active && writable) to determine collapsing a block entry into a table by calling kvm_pgtable_stage2_map(). But sometimes we may only need to relax permissions when trying to write to a page other than a block. In this condition,using kvm_pgtable_stage2_relax_perms() will be fine. The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup level at which a D-abort or I-abort occurred. By comparing granule of the fault lookup level with vma_pagesize, we can strictly distinguish conditions of calling kvm_pgtable_stage2_relax_perms() or kvm_pgtable_stage2_map(), and the above two cases will be well considered. Suggested-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201201201034.116760-4-wangyanan55@huawei.com
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