Enable to only update a subset of attributes. This is needed to be able to use the XArray for different use cases and make sure they don't interfere (see a following commit).
Cc: Chao Peng <chao.p.p...@linux.intel.com> Cc: Kees Cook <keesc...@chromium.org> Cc: Madhavan T. Venkataraman <madve...@linux.microsoft.com> Cc: Sean Christopherson <sea...@google.com> Cc: Yu Zhang <yu.c.zh...@linux.intel.com> Signed-off-by: Mickaël Salaün <m...@digikod.net> --- Changes since v1: * New patch --- arch/x86/kvm/mmu/mmu.c | 2 +- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 27 +++++++++++++++++++-------- 3 files changed, 21 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4d378d308762..d7010e09440d 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -7283,7 +7283,7 @@ static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot, for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) { if (hugepage_test_mixed(slot, gfn, level - 1) || - attrs != kvm_get_memory_attributes(kvm, gfn)) + !(attrs & kvm_get_memory_attributes(kvm, gfn))) return false; } return true; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 85b8648fd892..de68390ab0f2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2397,7 +2397,7 @@ bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm, bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, struct kvm_gfn_range *range); int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, - unsigned long attributes); + unsigned long attributes, unsigned long mask); static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0096ccfbb609..e2c178db17d5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2436,7 +2436,7 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES /* * Returns true if _all_ gfns in the range [@start, @end) have attributes - * matching @attrs. + * matching the @attrs bitmask. */ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, unsigned long attrs) @@ -2459,7 +2459,8 @@ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, entry = xas_next(&xas); } while (xas_retry(&xas, entry)); - if (xas.xa_index != index || xa_to_value(entry) != attrs) { + if (xas.xa_index != index || + (xa_to_value(entry) & attrs) != attrs) { has_attrs = false; break; } @@ -2553,7 +2554,7 @@ static bool kvm_pre_set_memory_attributes(struct kvm *kvm, /* Set @attributes for the gfn range [@start, @end). */ int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, - unsigned long attributes) + unsigned long attributes, unsigned long mask) { struct kvm_mmu_notifier_range pre_set_range = { .start = start, @@ -2572,11 +2573,8 @@ int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, .may_block = true, }; unsigned long i; - void *entry; int r = 0; - entry = attributes ? xa_mk_value(attributes) : NULL; - lockdep_assert_held(&kvm->slots_arch_lock); /* Nothing to do if the entire range as the desired attributes. */ @@ -2596,6 +2594,16 @@ int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, kvm_handle_gfn_range(kvm, &pre_set_range); for (i = start; i < end; i++) { + unsigned long value = 0; + void *entry; + + entry = xa_load(&kvm->mem_attr_array, i); + if (xa_is_value(entry)) + value = xa_to_value(entry) & ~mask; + + value |= attributes & mask; + entry = value ? xa_mk_value(value) : NULL; + r = xa_err(xa_store(&kvm->mem_attr_array, i, entry, GFP_KERNEL_ACCOUNT)); KVM_BUG_ON(r, kvm); @@ -2609,12 +2617,14 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, struct kvm_memory_attributes *attrs) { int r; + unsigned long attrs_mask; gfn_t start, end; /* flags is currently not used. */ if (attrs->flags) return -EINVAL; - if (attrs->attributes & ~kvm_supported_mem_attributes(kvm)) + attrs_mask = kvm_supported_mem_attributes(kvm); + if (attrs->attributes & ~attrs_mask) return -EINVAL; if (attrs->size == 0 || attrs->address + attrs->size < attrs->address) return -EINVAL; @@ -2632,7 +2642,8 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, BUILD_BUG_ON(sizeof(attrs->attributes) != sizeof(unsigned long)); mutex_lock(&kvm->slots_arch_lock); - r = kvm_vm_set_mem_attributes(kvm, start, end, attrs->attributes); + r = kvm_vm_set_mem_attributes(kvm, start, end, attrs->attributes, + attrs_mask); mutex_unlock(&kvm->slots_arch_lock); return r; } -- 2.42.1