diff options
| author | Ankit Agrawal <ankita@nvidia.com> | 2025-07-05 07:17:12 +0000 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2025-07-07 07:30:32 -0700 |
| commit | 8cc9dc1ae4fb075e29e2d5cf2386761d3497049a (patch) | |
| tree | 2edbdd098fc7bac30ac4206522fc4a745962e962 | |
| parent | 86731a2a651e58953fc949573895f2fa6d456841 (diff) | |
KVM: arm64: Rename the device variable to s2_force_noncacheable
To perform cache maintenance on a region of memory, KVM/arm64 relies on
that region having a cacheable alias in the kernel's address space which
can be used with CMO instructions.
The 'device' variable is somewhat of a misnomer, as it actually
indicates whether or not the stage-2 alias is allowed to have cacheable
memory attributes. The resulting stage-2 memory attributes are further
modified by VM_ALLOW_ANY_UNCACHED, selecting between Normal-NC or
Device-nGnRE depending on what the endpoint supports.
Rename the to s2_force_noncacheable such that its purpose is a bit more
obvious.
CC: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250705071717.5062-2-ankita@nvidia.com
[ Oliver: addressed typos, wound up rewriting changelog ]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
| -rw-r--r-- | arch/arm64/kvm/mmu.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 2942ec92c5a4..1601ab9527d4 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1478,7 +1478,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, int ret = 0; bool write_fault, writable, force_pte = false; bool exec_fault, mte_allowed; - bool device = false, vfio_allow_any_uc = false; + bool s2_force_noncacheable = false, vfio_allow_any_uc = false; unsigned long mmu_seq; phys_addr_t ipa = fault_ipa; struct kvm *kvm = vcpu->kvm; @@ -1653,7 +1653,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, * In both cases, we don't let transparent_hugepage_adjust() * change things at the last minute. */ - device = true; + s2_force_noncacheable = true; } else if (logging_active && !write_fault) { /* * Only actually map the page as writable if this was a write @@ -1662,7 +1662,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, writable = false; } - if (exec_fault && device) + if (exec_fault && s2_force_noncacheable) return -ENOEXEC; /* @@ -1695,7 +1695,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, * If we are not forced to use page mapping, check if we are * backed by a THP and thus use block mapping if possible. */ - if (vma_pagesize == PAGE_SIZE && !(force_pte || device)) { + if (vma_pagesize == PAGE_SIZE && !(force_pte || s2_force_noncacheable)) { if (fault_is_perm && fault_granule > PAGE_SIZE) vma_pagesize = fault_granule; else @@ -1709,7 +1709,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, } } - if (!fault_is_perm && !device && kvm_has_mte(kvm)) { + if (!fault_is_perm && !s2_force_noncacheable && kvm_has_mte(kvm)) { /* Check the VMM hasn't introduced a new disallowed VMA */ if (mte_allowed) { sanitise_mte_tags(kvm, pfn, vma_pagesize); @@ -1725,7 +1725,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault) prot |= KVM_PGTABLE_PROT_X; - if (device) { + if (s2_force_noncacheable) { if (vfio_allow_any_uc) prot |= KVM_PGTABLE_PROT_NORMAL_NC; else |