| Message ID | 20210322060158.1584-1-lushenming@huawei.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | KVM: arm64: Add VLPI migration support on GICv4.1 | expand |
On Mon, 22 Mar 2021 14:01:52 +0800, Shenming Lu wrote: > In GICv4.1, migration has been supported except for (directly-injected) > VLPI. And GICv4.1 Spec explicitly gives a way to get the VLPI's pending > state (which was crucially missing in GICv4.0). So we make VLPI migration > capable on GICv4.1 in this series. > > In order to support VLPI migration, we need to save and restore all > required configuration information and pending states of VLPIs. But > in fact, the configuration information of VLPIs has already been saved > (or will be reallocated on the dst host...) in vgic(kvm) migration. > So we only have to migrate the pending states of VLPIs specially. > > [...] Applied to next, thanks! [1/6] irqchip/gic-v3-its: Add a cache invalidation right after vPE unmapping commit: 301beaf19739cb6e640ed44e630e7da993f0ecc8 [2/6] irqchip/gic-v3-its: Drop the setting of PTZ altogether commit: c21bc068cdbe5613d3319ae171c3f2eb9f321352 [3/6] KVM: arm64: GICv4.1: Add function to get VLPI state commit: 80317fe4a65375fae668672a1398a0fb73eb9023 [4/6] KVM: arm64: GICv4.1: Try to save VLPI state in save_pending_tables commit: f66b7b151e00427168409f8c1857970e926b1e27 [5/6] KVM: arm64: GICv4.1: Restore VLPI pending state to physical side commit: 12df7429213abbfa9632ab7db94f629ec309a58b [6/6] KVM: arm64: GICv4.1: Give a chance to save VLPI state commit: 8082d50f4817ff6a7e08f4b7e9b18e5f8bfa290d Cheers, M.
On 2021/3/25 2:19, Marc Zyngier wrote: > On Mon, 22 Mar 2021 14:01:52 +0800, Shenming Lu wrote: >> In GICv4.1, migration has been supported except for (directly-injected) >> VLPI. And GICv4.1 Spec explicitly gives a way to get the VLPI's pending >> state (which was crucially missing in GICv4.0). So we make VLPI migration >> capable on GICv4.1 in this series. >> >> In order to support VLPI migration, we need to save and restore all >> required configuration information and pending states of VLPIs. But >> in fact, the configuration information of VLPIs has already been saved >> (or will be reallocated on the dst host...) in vgic(kvm) migration. >> So we only have to migrate the pending states of VLPIs specially. >> >> [...] > > Applied to next, thanks! Thanks a lot again for all the comments and suggestions. :-) Shenming > > [1/6] irqchip/gic-v3-its: Add a cache invalidation right after vPE unmapping > commit: 301beaf19739cb6e640ed44e630e7da993f0ecc8 > [2/6] irqchip/gic-v3-its: Drop the setting of PTZ altogether > commit: c21bc068cdbe5613d3319ae171c3f2eb9f321352 > [3/6] KVM: arm64: GICv4.1: Add function to get VLPI state > commit: 80317fe4a65375fae668672a1398a0fb73eb9023 > [4/6] KVM: arm64: GICv4.1: Try to save VLPI state in save_pending_tables > commit: f66b7b151e00427168409f8c1857970e926b1e27 > [5/6] KVM: arm64: GICv4.1: Restore VLPI pending state to physical side > commit: 12df7429213abbfa9632ab7db94f629ec309a58b > [6/6] KVM: arm64: GICv4.1: Give a chance to save VLPI state > commit: 8082d50f4817ff6a7e08f4b7e9b18e5f8bfa290d > > Cheers, > > M. >
Hi, In GICv4.1, migration has been supported except for (directly-injected) VLPI. And GICv4.1 Spec explicitly gives a way to get the VLPI's pending state (which was crucially missing in GICv4.0). So we make VLPI migration capable on GICv4.1 in this series. In order to support VLPI migration, we need to save and restore all required configuration information and pending states of VLPIs. But in fact, the configuration information of VLPIs has already been saved (or will be reallocated on the dst host...) in vgic(kvm) migration. So we only have to migrate the pending states of VLPIs specially. Below is the related workflow in migration. On the save path: In migration completion: pause all vCPUs | call each VM state change handler: pause other devices (just keep from sending interrupts, and such as VFIO migration protocol has already realized it [1]) | flush ITS tables into guest RAM | flush RDIST pending tables (also flush VLPI pending states here) | ... On the resume path: load each device's state: restore ITS tables (include pending tables) from guest RAM | for other (PCI) devices (paused), if configured to have VLPIs, establish the forwarding paths of their VLPIs (and transfer the pending states from kvm's vgic to VPT here) We have tested this series in VFIO migration, and found some related issues in QEMU [2]. Links: [1] vfio: UAPI for migration interface for device state: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a8a24f3f6e38103b77cf399c38eb54e1219d00d6 [2] vfio: Some fixes and optimizations for VFIO migration: https://patchwork.ozlabs.org/project/qemu-devel/cover/20210310030233.1133-1-lushenming@huawei.com/ History: v4 -> v5 - Lock the whole pending state read/write sequence. (in Patch 5, from Marc) v3 -> v4 - Nit fixes. - Add a CPU cache invalidation right after unmapping the vPE. (Patch 1) - Drop the setting of PTZ altogether. (Patch 2) - Bail out if spot !vgic_initialized(). (in Patch 4) - Communicate the state change (clear pending_latch) via vgic_queue_irq_unlock. (in Patch 5) Thanks a lot for the suggestions from Marc! v2 -> v3 - Add the vgic initialized check to ensure that the allocation and enabling of the doorbells have already been done before unmapping the vPEs. - Check all get_vlpi_state related conditions in save_pending_tables in one place. - Nit fixes. v1 -> v2: - Get the VLPI state from the KVM side. - Nit fixes. Thanks, Shenming Marc Zyngier (1): irqchip/gic-v3-its: Add a cache invalidation right after vPE unmapping Shenming Lu (4): irqchip/gic-v3-its: Drop the setting of PTZ altogether KVM: arm64: GICv4.1: Add function to get VLPI state KVM: arm64: GICv4.1: Try to save VLPI state in save_pending_tables KVM: arm64: GICv4.1: Give a chance to save VLPI state Zenghui Yu (1): KVM: arm64: GICv4.1: Restore VLPI pending state to physical side .../virt/kvm/devices/arm-vgic-its.rst | 2 +- arch/arm64/kvm/vgic/vgic-its.c | 6 +- arch/arm64/kvm/vgic/vgic-v3.c | 66 +++++++++++++++++-- arch/arm64/kvm/vgic/vgic-v4.c | 38 +++++++++++ arch/arm64/kvm/vgic/vgic.h | 1 + drivers/irqchip/irq-gic-v3-its.c | 21 +++++- 6 files changed, 122 insertions(+), 12 deletions(-)