kvm_s390_pv_dump_stor_state(9)

✨ NAME ✨

okay so bestie, welcome to the kvm_s390_pv_dump_stor_state(9) page from the Kernel API Manual 🫶💖

The NAME line is literally just kvm_s390_pv_dump_stor_state — dash, then nothing. No extra one-liner, no secret subtitle. We are not inventing one, periodt. 💅

🦋 SYNOPSIS 🦋

The function is declared exactly like this, no cap:

int kvm_s390_pv_dump_stor_state (struct kvm *kvm , void __user *buff_user , u64 *gaddr , u64 buff_user_len , u16 *rc , u16 *rrc );

🎀 ARGUMENTS 🎀

These are the parameters, bestie — every single one matters:

• kvm — pointer to the guest's KVM struct, iykyk.
• buff_user — Userspace pointer where we will write the results to. That's where the data goes 💖
• gaddr — Starting absolute guest address for which the storage state is requested.
• buff_user_len — Length of the buff_user buffer.
• rc — Pointer to where the uvcb return code is stored.
• rrc — Pointer to where the uvcb return reason code is stored.

💅 DESCRIPTION 💅

okay so the actual job: stores buff_len bytes of tweak component values to buff_user, starting with the 1MB block specified by the absolute guest address (gaddr). ✨

The gaddr pointer will be updated with the last address for which data was written when returning to userspace. 🫶

heads up, bestie: buff_user might be written to even if an error rc is returned. For instance if we encounter a fault after writing the first page of data. 😭

🔒 CONTEXT 🔒

kvm->lock needs to be held. That's it. That's the context. Do not forget it, bestie. 💅

🌈 RETURN 🌈

• 0 on success — slay.
• -ENOMEM if allocating the cache fails.
• -EINVAL if gaddr is not aligned to 1MB.
• -EINVAL if buff_user_len is not aligned to uv_info.conf_dump_storage_state_len.
• -EINVAL if the UV call fails, rc and rrc will be set in this case.
• -EFAULT if copying the result to buff_user failed.

🫶 SEE ALSO 🫶

Kernel file ./arch/s390/kvm/s390/pv.c has the source-lore, and these are the linked manpage besties:

• should_export_before_import(9)
• kvm_s390_pv_make_secure(9)
• kvm_s390_pv_destroy_page(9)
• struct pv_vm_to_be_destroyed(9)
• kvm_s390_pv_dispose_one_leftover(9)
• kvm_s390_pv_set_aside(9)
• kvm_s390_pv_deinit_vm(9)
• kvm_s390_pv_deinit_cleanup_all(9)
• kvm_s390_pv_deinit_aside_vm(9)
• kvm_s390_pv_dump_complete(9)

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mwah 💋 that's the page! The source line was ./arch/s390/kvm/s390, and the date stamp says October 2026. Catch you in the next manpage, bestie 🫶✨