mbox series

[v4,00/10] KVM: arm64: Avoid serializing LPI get() / put()

Message ID 20240221054253.3848076-1-oliver.upton@linux.dev
Headers
Series KVM: arm64: Avoid serializing LPI get() / put() |

Message

Oliver Upton Feb. 21, 2024, 5:42 a.m. UTC 
  Addressing a few more goofs that Zenghui was kind enough to point out.
Clearly all of the bugs have been found and addressed at this point.

v2: https://lore.kernel.org/kvmarm/20240213093250.3960069-1-oliver.upton@linux.dev/
v3: https://lore.kernel.org/kvmarm/20240216184153.2714504-1-oliver.upton@linux.dev/

v3 -> v4:
 - Actually walk the LPI INTID range in vgic_copy_lpi_list() (Zenghui)
 - Ensure xa_lock is taken w/ IRQs disabled, even after purging usage of
   the lpi_list_lock (Zenghui)
 - Document the lock ordering (Marc)

Oliver Upton (10):
  KVM: arm64: vgic: Store LPIs in an xarray
  KVM: arm64: vgic: Use xarray to find LPI in vgic_get_lpi()
  KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIs
  KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list()
  KVM: arm64: vgic: Get rid of the LPI linked-list
  KVM: arm64: vgic: Use atomics to count LPIs
  KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner
  KVM: arm64: vgic: Rely on RCU protection in vgic_get_lpi()
  KVM: arm64: vgic: Ensure the irq refcount is nonzero when taking a ref
  KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq()

 arch/arm64/kvm/vgic/vgic-debug.c |  2 +-
 arch/arm64/kvm/vgic/vgic-init.c  |  4 ++-
 arch/arm64/kvm/vgic/vgic-its.c   | 55 +++++++++++++++++++----------
 arch/arm64/kvm/vgic/vgic-v3.c    |  3 +-
 arch/arm64/kvm/vgic/vgic.c       | 60 +++++++++++---------------------
 arch/arm64/kvm/vgic/vgic.h       | 15 +++++---
 include/kvm/arm_vgic.h           |  9 ++---
 7 files changed, 79 insertions(+), 69 deletions(-)


base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d

Comments

Marc Zyngier Feb. 23, 2024, 2:23 p.m. UTC | #1 
On Wed, 21 Feb 2024 05:42:43 +0000,
Oliver Upton <oliver.upton@linux.dev> wrote:
> 
> Addressing a few more goofs that Zenghui was kind enough to point out.
> Clearly all of the bugs have been found and addressed at this point.
> 
> v2: https://lore.kernel.org/kvmarm/20240213093250.3960069-1-oliver.upton@linux.dev/
> v3: https://lore.kernel.org/kvmarm/20240216184153.2714504-1-oliver.upton@linux.dev/
> 
> v3 -> v4:
>  - Actually walk the LPI INTID range in vgic_copy_lpi_list() (Zenghui)
>  - Ensure xa_lock is taken w/ IRQs disabled, even after purging usage of
>    the lpi_list_lock (Zenghui)
>  - Document the lock ordering (Marc)

This is looking good so far. I'll take it for a ride shortly, but in
the meantime:

Reviewed-by: Marc Zyngier <maz@kernel.org>

	M.
Oliver Upton Feb. 23, 2024, 9:52 p.m. UTC | #2 
On Wed, 21 Feb 2024 05:42:43 +0000, Oliver Upton wrote:
> Addressing a few more goofs that Zenghui was kind enough to point out.
> Clearly all of the bugs have been found and addressed at this point.
> 
> v2: https://lore.kernel.org/kvmarm/20240213093250.3960069-1-oliver.upton@linux.dev/
> v3: https://lore.kernel.org/kvmarm/20240216184153.2714504-1-oliver.upton@linux.dev/
> 
> v3 -> v4:
>  - Actually walk the LPI INTID range in vgic_copy_lpi_list() (Zenghui)
>  - Ensure xa_lock is taken w/ IRQs disabled, even after purging usage of
>    the lpi_list_lock (Zenghui)
>  - Document the lock ordering (Marc)
> 
> [...]

Applied to kvmarm/next, thanks!

[01/10] KVM: arm64: vgic: Store LPIs in an xarray
        https://git.kernel.org/kvmarm/kvmarm/c/1d6f83f60f79
[02/10] KVM: arm64: vgic: Use xarray to find LPI in vgic_get_lpi()
        https://git.kernel.org/kvmarm/kvmarm/c/5a021df71916
[03/10] KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIs
        https://git.kernel.org/kvmarm/kvmarm/c/49f0a468a158
[04/10] KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list()
        https://git.kernel.org/kvmarm/kvmarm/c/2798683b8c80
[05/10] KVM: arm64: vgic: Get rid of the LPI linked-list
        https://git.kernel.org/kvmarm/kvmarm/c/9880835af78e
[06/10] KVM: arm64: vgic: Use atomics to count LPIs
        https://git.kernel.org/kvmarm/kvmarm/c/05f4d4f5d462
[07/10] KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner
        https://git.kernel.org/kvmarm/kvmarm/c/a5c7f011cb58
[08/10] KVM: arm64: vgic: Rely on RCU protection in vgic_get_lpi()
        https://git.kernel.org/kvmarm/kvmarm/c/864d4304ec1e
[09/10] KVM: arm64: vgic: Ensure the irq refcount is nonzero when taking a ref
        https://git.kernel.org/kvmarm/kvmarm/c/50ac89bb7092
[10/10] KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq()
        https://git.kernel.org/kvmarm/kvmarm/c/e27f2d561fee

--
Best,
Oliver