From: Wei Liu <[email protected]> Allow userspace to provide fewer than MSHV_NUM_CPU_FEATURES_BANKS banks for the create-partition v2 ioctl. Preserve the default disabled-feature mask for omitted banks instead of rejecting the ioctl or overwriting all banks.
Signed-off-by: Wei Liu <[email protected]> --- drivers/hv/mshv_root_main.c | 12 ++---------- include/uapi/linux/mshv.h | 3 ++- 2 files changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 11d3c86050b4..729916e1eacf 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -2423,20 +2423,12 @@ static long mshv_ioctl_process_pt_flags(void __user *user_arg, u64 *pt_flags, args.pt_isolation >= MSHV_PT_ISOLATION_COUNT) return -EINVAL; - if (args.pt_num_cpu_fbanks != MSHV_NUM_CPU_FEATURES_BANKS || + if (args.pt_num_cpu_fbanks > MSHV_NUM_CPU_FEATURES_BANKS || mshv_field_nonzero(args, pt_rsvd) || mshv_field_nonzero(args, pt_rsvd1)) return -EINVAL; - /* - * Note this assumes MSHV_NUM_CPU_FEATURES_BANKS will never - * change and equals HV_PARTITION_PROCESSOR_FEATURES_BANKS - * (i.e. 2). - * - * Further banks (index >= 2) will be modifiable as 'early' - * properties via the set partition property hypercall. - */ - for (i = 0; i < HV_PARTITION_PROCESSOR_FEATURES_BANKS; i++) + for (i = 0; i < args.pt_num_cpu_fbanks; i++) disabled_procs->as_uint64[i] = args.pt_cpu_fbanks[i]; #if IS_ENABLED(CONFIG_X86_64) diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h index 4e7f3038f0c6..6d6e0fda63bd 100644 --- a/include/uapi/linux/mshv.h +++ b/include/uapi/linux/mshv.h @@ -66,7 +66,8 @@ struct mshv_create_partition { * This is extended version of the above initial MSHV_CREATE_PARTITION * ioctl and allows for following additional parameters: * - * @pt_num_cpu_fbanks: Must be set to MSHV_NUM_CPU_FEATURES_BANKS. + * @pt_num_cpu_fbanks: Number of processor feature banks provided. Must not + * exceed MSHV_NUM_CPU_FEATURES_BANKS. * @pt_cpu_fbanks: Disabled processor feature banks array. * @pt_disabled_xsave: Disabled xsave feature bits. * -- 2.43.0
