[PATCH RFC v2 25/27] KVM: arm64: Disable MTE if tag storage is enabled
From: Alexandru Elisei <hidden>
Date: 2023-11-19 16:59:51
Also in:
kvmarm, linux-arch, linux-arm-kernel, linux-fsdevel, linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
KVM allows MTE enabled VMs to be created when the backing VMA does not have MTE enabled. Without changes to how KVM allocates memory for a VM, it is impossible at the moment to discern when the corresponding tag storage needs to be reserved. For now, disable MTE in KVM if tag storage is enabled. Signed-off-by: Alexandru Elisei <redacted> --- arch/arm64/kvm/arm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e5f75f1f1085..5b33c532c62a 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c@@ -29,6 +29,7 @@ #include <linux/uaccess.h> #include <asm/ptrace.h> #include <asm/mman.h> +#include <asm/mte_tag_storage.h> #include <asm/tlbflush.h> #include <asm/cacheflush.h> #include <asm/cpufeature.h>
@@ -86,7 +87,8 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, break; case KVM_CAP_ARM_MTE: mutex_lock(&kvm->lock); - if (!system_supports_mte() || kvm->created_vcpus) { + if (!system_supports_mte() || tag_storage_enabled() || + kvm->created_vcpus) { r = -EINVAL; } else { r = 0;
@@ -279,7 +281,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = 1; break; case KVM_CAP_ARM_MTE: - r = system_supports_mte(); + r = system_supports_mte() && !tag_storage_enabled(); break; case KVM_CAP_STEAL_TIME: r = kvm_arm_pvtime_supported();
--
2.42.1