[v2] target/riscv/kvm: Add SBI STA register sync and migration support

[PATCH v2 0/3] target/riscv/kvm: Add SBI STA register sync and migration support

Wang Yechao posted 3 patches 1 day, 18 hours ago

Diff against v1
Download series mbox

target/riscv/cpu.h           |   6 ++
target/riscv/kvm/kvm-cpu.c   | 122 +++++++++++++++++++++++++++++++++++
target/riscv/kvm/kvm_riscv.h |   1 +
target/riscv/machine.c       |  18 ++++++
4 files changed, 147 insertions(+)

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[PATCH v2 0/3] target/riscv/kvm: Add SBI STA register sync and migration support

Posted by Wang Yechao 1 day, 18 hours ago

KVM already exposes the SBI STA extension and its shmem address through
the one-reg interface, but QEMU does not consume it. As a result, the
guest-configured shmem address is not kept in sync between KVM and QEMU,
and is lost on migration, breaking STA for the guest after live
migration.

This series probes for SBI STA support via get-reg-list, synchronizes
the shmem address (shmem_lo/shmem_hi) between KVM and QEMU (skipping the
put at reset, since the address is configured by the guest), and saves
the address in vmstate so STA keeps working after live migration. Only
the STA shmem address is saved for now; other SBI state can be appended
to kvm_sbi_state later.

Changes in v2:
 - patch03, only save the sbi sta state if kvm sbi sta supported.
 - rebase on riscv-to-apply.next.

 - Link to v1:
 https://lore.kernel.org/qemu-devel/20261017145211.219258-1-wang.yechao255@zte.com.cn/

Wang Yechao (3):
  target/riscv/kvm: Detect SBI STA extension support
  target/riscv/kvm: Sync SBI STA shmem registers with KVM
  target/riscv: Add SBI STA state to vmstate

 target/riscv/cpu.h           |   6 ++
 target/riscv/kvm/kvm-cpu.c   | 122 +++++++++++++++++++++++++++++++++++
 target/riscv/kvm/kvm_riscv.h |   1 +
 target/riscv/machine.c       |  18 ++++++
 4 files changed, 147 insertions(+)

-- 
2.27.0