Re: [PATCH v10 2/9] KVM: Introduce per-page memory attributes
From: Borislav Petkov <bp@alien8.de>
Date: 2022-12-16 15:09:24
Also in:
kvm, linux-arch, linux-doc, linux-fsdevel, linux-mm, lkml, qemu-devel
On Fri, Dec 02, 2022 at 02:13:40PM +0800, Chao Peng wrote:
quoted hunk ↗ jump to hunk
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1782c4555d94..7f0f5e9f2406 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c@@ -1150,6 +1150,9 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) spin_lock_init(&kvm->mn_invalidate_lock); rcuwait_init(&kvm->mn_memslots_update_rcuwait); xa_init(&kvm->vcpu_array); +#ifdef CONFIG_HAVE_KVM_MEMORY_ATTRIBUTES + xa_init(&kvm->mem_attr_array); +#endif
if (IS_ENABLED(CONFIG_HAVE_KVM_MEMORY_ATTRIBUTES)) ... would at least remove the ugly ifdeffery. Or you could create wrapper functions for that xa_init() and xa_destroy() and put the ifdeffery in there.
quoted hunk ↗ jump to hunk
@@ -2323,6 +2329,49 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, } #endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ +#ifdef CONFIG_HAVE_KVM_MEMORY_ATTRIBUTES +static u64 kvm_supported_mem_attributes(struct kvm *kvm)
I guess that function should have a verb in the name: kvm_get_supported_mem_attributes()
+static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm,
+ struct kvm_memory_attributes *attrs)
+{
+ gfn_t start, end;
+ unsigned long i;
+ void *entry;
+ u64 supported_attrs = kvm_supported_mem_attributes(kvm);
+
+ /* flags is currently not used. */
+ if (attrs->flags)
+ return -EINVAL;
+ if (attrs->attributes & ~supported_attrs)
+ return -EINVAL;
+ if (attrs->size == 0 || attrs->address + attrs->size < attrs->address)
+ return -EINVAL;
+ if (!PAGE_ALIGNED(attrs->address) || !PAGE_ALIGNED(attrs->size))
+ return -EINVAL;Dunno, shouldn't those issue some sort of an error message so that the caller knows where it failed? Or at least return different retvals which signal what the problem is?
+ start = attrs->address >> PAGE_SHIFT; + end = (attrs->address + attrs->size - 1 + PAGE_SIZE) >> PAGE_SHIFT; + + entry = attrs->attributes ? xa_mk_value(attrs->attributes) : NULL; + + mutex_lock(&kvm->lock); + for (i = start; i < end; i++) + if (xa_err(xa_store(&kvm->mem_attr_array, i, entry, + GFP_KERNEL_ACCOUNT))) + break; + mutex_unlock(&kvm->lock); + + attrs->address = i << PAGE_SHIFT; + attrs->size = (end - i) << PAGE_SHIFT; + + return 0; +}
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette