The existing mshv create partition ioctl does not provide a way to specify which cpu features are enabled in the guest. Instead, it attempts to enable all features and those that are not supported are silently disabled by the hypervisor. This was done to reduce unnecessary complexity and is sufficient for many cases. However, new scenarios require fine-grained control over these features. Define a new mshv_create_partition_v2 structure which supports passing the disabled processor and xsave feature bits through to the create partition hypercall directly. Introduce a new flag MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES which enables the new structure. If unset, the original mshv_create_partition struct is used, with the old behavior of enabling all features.
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| @@ -26,6 +26,7 @@ enum { · 25 unmodified lines | ||
| 26 | 26 | MSHV_PT_BIT_LAPIC, |
| 27 | 27 | MSHV_PT_BIT_X2APIC, |
| 28 | 28 | MSHV_PT_BIT_GPA_SUPER_PAGES, |
| 29 | + MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES, | |
| 29 | 30 | MSHV_PT_BIT_COUNT, |
| 30 | 31 | }; |
| 31 | 32 | |
| @@ -41,6 +42,8 @@ enum { · 9 unmodified lines | ||
| 41 | 42 | * @pt_flags: Bitmask of 1 << MSHV_PT_BIT_* |
| 42 | 43 | * @pt_isolation: MSHV_PT_ISOLATION_* |
| 43 | 44 | * |
| 45 | + * This is the initial/v1 version for backward compatibility. | |
| 46 | + * | |
| 44 | 47 | * Returns a file descriptor to act as a handle to a guest partition. |
| 45 | 48 | * At this point the partition is not yet initialized in the hypervisor. |
| 46 | 49 | * Some operations must be done with the partition in this state, e.g. setting |
| @@ -52,6 +55,37 @@ struct mshv_create_partition { · 5 unmodified lines | ||
| 52 | 55 | __u64 pt_isolation; |
| 53 | 56 | }; |
| 54 | 57 | |
| 58 | +#define MSHV_NUM_CPU_FEATURES_BANKS 2 | |
| 59 | + | |
| 60 | +/** | |
| 61 | + * struct mshv_create_partition_v2 | |
| 62 | + * | |
| 63 | + * This is extended version of the above initial MSHV_CREATE_PARTITION | |
| 64 | + * ioctl and allows for following additional parameters: | |
| 65 | + * | |
| 66 | + * @pt_num_cpu_fbanks: Must be set to MSHV_NUM_CPU_FEATURES_BANKS. | |
| 67 | + * @pt_cpu_fbanks: Disabled processor feature banks array. | |
| 68 | + * @pt_disabled_xsave: Disabled xsave feature bits. | |
| 69 | + * | |
| 70 | + * pt_cpu_fbanks and pt_disabled_xsave are passed through as-is to the create | |
| 71 | + * partition hypercall. | |
| 72 | + * | |
| 73 | + * Returns : same as above original mshv_create_partition | |
| 74 | + */ | |
| 75 | +struct mshv_create_partition_v2 { | |
| 76 | + __u64 pt_flags; | |
| 77 | + __u64 pt_isolation; | |
| 78 | + __u16 pt_num_cpu_fbanks; | |
| 79 | + __u8 pt_rsvd[6]; /* MBZ */ | |
| 80 | + __u64 pt_cpu_fbanks[MSHV_NUM_CPU_FEATURES_BANKS]; | |
| 81 | + __u64 pt_rsvd1[2]; /* MBZ */ | |
| 82 | +#if defined(__x86_64__) | |
| 83 | + __u64 pt_disabled_xsave; | |
| 84 | +#else | |
| 85 | + __u64 pt_rsvd2; /* MBZ */ | |
| 86 | +#endif | |
| 87 | +} __packed; | |
| 88 | + | |
| 55 | 89 | /* /dev/mshv */ |
| 56 | 90 | #define MSHV_CREATE_PARTITION _IOW(MSHV_IOCTL, 0x00, struct mshv_create_partition) |
| 57 | 91 | |