From ea7fc1bb1cd1b92b42b1d9273ce7e231d3dc9321 Mon Sep 17 00:00:00 2001 From: Steven Price Date: Mon, 21 Jun 2021 12:17:12 +0100 Subject: KVM: arm64: Introduce MTE VM feature Add a new VM feature 'KVM_ARM_CAP_MTE' which enables memory tagging for a VM. This will expose the feature to the guest and automatically tag memory pages touched by the VM as PG_mte_tagged (and clear the tag storage) to ensure that the guest cannot see stale tags, and so that the tags are correctly saved/restored across swap. Actually exposing the new capability to user space happens in a later patch. Reviewed-by: Catalin Marinas Signed-off-by: Steven Price [maz: move VM_SHARED sampling into the critical section] Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210621111716.37157-3-steven.price@arm.com --- include/uapi/linux/kvm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 79d9c44d1ad7..d4da58ddcad7 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1083,6 +1083,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_SGX_ATTRIBUTE 196 #define KVM_CAP_VM_COPY_ENC_CONTEXT_FROM 197 #define KVM_CAP_PTP_KVM 198 +#define KVM_CAP_ARM_MTE 199 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3 From f0376edb1ddcab19a473b4bf1fbd5b6bbed3705b Mon Sep 17 00:00:00 2001 From: Steven Price Date: Mon, 21 Jun 2021 12:17:15 +0100 Subject: KVM: arm64: Add ioctl to fetch/store tags in a guest The VMM may not wish to have it's own mapping of guest memory mapped with PROT_MTE because this causes problems if the VMM has tag checking enabled (the guest controls the tags in physical RAM and it's unlikely the tags are correct for the VMM). Instead add a new ioctl which allows the VMM to easily read/write the tags from guest memory, allowing the VMM's mapping to be non-PROT_MTE while the VMM can still read/write the tags for the purpose of migration. Reviewed-by: Catalin Marinas Signed-off-by: Steven Price Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210621111716.37157-6-steven.price@arm.com --- include/uapi/linux/kvm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index d4da58ddcad7..da1edd2b4046 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1429,6 +1429,7 @@ struct kvm_s390_ucas_mapping { /* Available with KVM_CAP_PMU_EVENT_FILTER */ #define KVM_SET_PMU_EVENT_FILTER _IOW(KVMIO, 0xb2, struct kvm_pmu_event_filter) #define KVM_PPC_SVM_OFF _IO(KVMIO, 0xb3) +#define KVM_ARM_MTE_COPY_TAGS _IOR(KVMIO, 0xb4, struct kvm_arm_copy_mte_tags) /* ioctl for vm fd */ #define KVM_CREATE_DEVICE _IOWR(KVMIO, 0xe0, struct kvm_create_device) -- cgit v1.2.3