From 2b953ea348128ef4d70b0e21f01c1bdee48ee4dc Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Fri, 28 Sep 2018 14:39:18 +0100 Subject: [PATCH] KVM: Allow 2048-bit register access via ioctl interface MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Arm SVE architecture defines registers that are up to 2048 bits in size (with some possibility of further future expansion). In order to avoid the need for an excessively large number of ioctls when saving and restoring a vcpu's registers, this patch adds a #define to make support for individual 2048-bit registers through the KVM_{GET,SET}_ONE_REG ioctl interface official. This will allow each SVE register to be accessed in a single call. There are sufficient spare bits in the register id size field for this change, so there is no ABI impact, providing that KVM_GET_REG_LIST does not enumerate any 2048-bit register unless userspace explicitly opts in to the relevant architecture-specific features. Signed-off-by: Dave Martin Reviewed-by: Alex Bennée Tested-by: zhang.lei Signed-off-by: Marc Zyngier --- include/uapi/linux/kvm.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 6d4ea4b6c922..dc77a5a3648d 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1145,6 +1145,7 @@ struct kvm_dirty_tlb { #define KVM_REG_SIZE_U256 0x0050000000000000ULL #define KVM_REG_SIZE_U512 0x0060000000000000ULL #define KVM_REG_SIZE_U1024 0x0070000000000000ULL +#define KVM_REG_SIZE_U2048 0x0080000000000000ULL struct kvm_reg_list { __u64 n; /* number of regs */