[Qemu-commits] [qemu/qemu] 3f481e: ppc/spapr: Introduce SPAPR_IRQ_NR_IPIS to refer IR...

[Alex Bennée]

  Branch: refs/heads/staging-7.2
  Home:   https://github.com/qemu/qemu
  Commit: 3f481e33056c83044fcf7a6873be04ffc47b195a
      
https://github.com/qemu/qemu/commit/3f481e33056c83044fcf7a6873be04ffc47b195a
  Author: Harsh Prateek Bora <harshpb@linux.ibm.com>
  Date:   2024-04-16 (Tue, 16 Apr 2024)

  Changed paths:
    M hw/ppc/spapr_irq.c
    M include/hw/ppc/spapr_irq.h

  Log Message:
  -----------
  ppc/spapr: Introduce SPAPR_IRQ_NR_IPIS to refer IRQ range for CPU IPIs.

spapr_irq_init currently uses existing macro SPAPR_XIRQ_BASE to refer to
the range of CPU IPIs during initialization of nr-irqs property.
It is more appropriate to have its own define which can be further
reused as appropriate for correct interpretation.

Suggested-by: Cedric Le Goater <clg@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Kowshik Jois <kowsjois@linux.ibm.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
(cherry picked from commit 2df5c1f5b014126595a26c6797089d284a3b211c)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>


  Commit: ab4a60c1b749c7ec19c16f3e900943b59996ab5e
      
https://github.com/qemu/qemu/commit/ab4a60c1b749c7ec19c16f3e900943b59996ab5e
  Author: Harsh Prateek Bora <harshpb@linux.ibm.com>
  Date:   2024-04-16 (Tue, 16 Apr 2024)

  Changed paths:
    M hw/ppc/spapr.c

  Log Message:
  -----------
  ppc/spapr: Initialize max_cpus limit to SPAPR_IRQ_NR_IPIS.

Initialize the machine specific max_cpus limit as per the maximum range
of CPU IPIs available. Keeping between 4096 to 8192 will throw IRQ not
free error due to XIVE/XICS limitation and keeping beyond 8192 will hit
assert in tcg_region_init or spapr_xive_claim_irq.

Logs:

Without patch fix:

[root@host build]# qemu-system-ppc64 -accel tcg -smp 10,maxcpus=4097
qemu-system-ppc64: IRQ 4096 is not free
[root@host build]#

On LPAR:
[root@host build]# qemu-system-ppc64 -accel tcg -smp 10,maxcpus=8193
**
ERROR:../tcg/region.c:774:tcg_region_init: assertion failed:
(region_size >= 2 * page_size)
Bail out! ERROR:../tcg/region.c:774:tcg_region_init: assertion failed:
(region_size >= 2 * page_size)
Aborted (core dumped)
[root@host build]#

On x86:
[root@host build]# qemu-system-ppc64 -accel tcg -smp 10,maxcpus=8193
qemu-system-ppc64: ../hw/intc/spapr_xive.c:596: spapr_xive_claim_irq:
Assertion `lisn < xive->nr_irqs' failed.
Aborted (core dumped)
[root@host build]#

With patch fix:
[root@host build]# qemu-system-ppc64 -accel tcg -smp 10,maxcpus=4097
qemu-system-ppc64: Invalid SMP CPUs 4097. The max CPUs supported by
machine 'pseries-8.2' is 4096
[root@host build]#

Reported-by: Kowshik Jois <kowsjois@linux.ibm.com>
Tested-by: Kowshik Jois <kowsjois@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
(cherry picked from commit c4f91d7b7be76c47015521ab0109c6e998a369b0)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>


Compare: https://github.com/qemu/qemu/compare/4741ae6b8ee7...ab4a60c1b749

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