When qemu runs without kvm acceleration the ACPI executions take a great
amount of time. If they take more than the default time (30sec), the
ACPI calls fail and the system might not behave correctly.
Now the _PRT table is computed on the fly. We can drastically reduce the
execution of the _PRT method if we return a pre-computed table.
Without this patch:
[ 51.343484] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[ 51.527032] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[ 51.530049] virtio-pci 0000:00:02.0: can't derive routing for PCI INT A
[ 51.530797] virtio-pci 0000:00:02.0: PCI INT A: no GSI
[ 81.922901] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[ 82.103534] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[ 82.106088] virtio-pci 0000:00:04.0: can't derive routing for PCI INT A
[ 82.106761] virtio-pci 0000:00:04.0: PCI INT A: no GSI
[ 112.192568] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[ 112.486687] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[ 112.489554] virtio-pci 0000:00:05.0: can't derive routing for PCI INT A
[ 112.490027] virtio-pci 0000:00:05.0: PCI INT A: no GSI
[ 142.559448] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[ 142.718596] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[ 142.722889] virtio-pci 0000:00:06.0: can't derive routing for PCI INT A
[ 142.724578] virtio-pci 0000:00:06.0: PCI INT A: no GSI
With this patch:
[ 22.938076] ACPI: \_SB_.LNKB: Enabled at IRQ 10
[ 24.214002] ACPI: \_SB_.LNKD: Enabled at IRQ 11
[ 25.465170] ACPI: \_SB_.LNKA: Enabled at IRQ 10
[ 27.944920] ACPI: \_SB_.LNKC: Enabled at IRQ 11
ACPI disassembly:
Scope (PCI0)
{
Method (_PRT, 0, NotSerialized) // _PRT: PCI Routing Table
{
Return (Package (0x80)
{
Package (0x04)
{
0xFFFF,
Zero,
LNKD,
Zero
},
Package (0x04)
{
0xFFFF,
One,
LNKA,
Zero
},
Package (0x04)
{
0xFFFF,
0x02,
LNKB,
Zero
},
Package (0x04)
{
0xFFFF,
0x03,
LNKC,
Zero
},
Package (0x04)
{
0x0001FFFF,
Zero,
LNKS,
Zero
},
Context: https://lore.kernel.org/virtualization/20240417145544.38d7b482@imammedo.users.ipa.redhat.com/T/#t
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240814115736.1580337-3-ribalda@chromium.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
99cb2c6c7b