* [PATCH v2] pci: ensure valid link status bits for downstream ports
@ 2024-12-03 12:19 Sebastian Ott
2024-12-03 14:28 ` Alex Williamson
2025-01-17 6:21 ` Michael Tokarev
0 siblings, 2 replies; 5+ messages in thread
From: Sebastian Ott @ 2024-12-03 12:19 UTC (permalink / raw)
To: Alex Williamson, Marcel Apfelbaum, Michael S . Tsirkin
Cc: qemu-devel, Sebastian Ott, Zhenyu Zhang
PCI hotplug for downstream endpoints on arm fails because Linux'
PCIe hotplug driver doesn't like the QEMU provided LNKSTA:
pcieport 0000:08:01.0: pciehp: Slot(2): Card present
pcieport 0000:08:01.0: pciehp: Slot(2): Link Up
pcieport 0000:08:01.0: pciehp: Slot(2): Cannot train link: status 0x2000
There's 2 cases where LNKSTA isn't setup properly:
* the downstream device has no express capability
* max link width of the bridge is 0
Move the sanity checks added via 88c869198aa63
("pci: Sanity test minimum downstream LNKSTA") outside of the
branch to make sure downstream ports always have a valid LNKSTA.
Signed-off-by: Sebastian Ott <sebott@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
---
hw/pci/pcie.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 0b455c8654..1b12db6fa2 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -1113,18 +1113,22 @@ void pcie_sync_bridge_lnk(PCIDevice *bridge_dev)
if ((lnksta & PCI_EXP_LNKSTA_NLW) > (lnkcap & PCI_EXP_LNKCAP_MLW)) {
lnksta &= ~PCI_EXP_LNKSTA_NLW;
lnksta |= lnkcap & PCI_EXP_LNKCAP_MLW;
- } else if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
- lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
}
if ((lnksta & PCI_EXP_LNKSTA_CLS) > (lnkcap & PCI_EXP_LNKCAP_SLS)) {
lnksta &= ~PCI_EXP_LNKSTA_CLS;
lnksta |= lnkcap & PCI_EXP_LNKCAP_SLS;
- } else if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
- lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
}
}
+ if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
+ lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
+ }
+
+ if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
+ lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
+ }
+
pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA, lnksta &
--
2.42.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2] pci: ensure valid link status bits for downstream ports
2024-12-03 12:19 [PATCH v2] pci: ensure valid link status bits for downstream ports Sebastian Ott
@ 2024-12-03 14:28 ` Alex Williamson
2024-12-17 15:52 ` Sebastian Ott
2025-01-07 16:48 ` Sebastian Ott
2025-01-17 6:21 ` Michael Tokarev
1 sibling, 2 replies; 5+ messages in thread
From: Alex Williamson @ 2024-12-03 14:28 UTC (permalink / raw)
To: Sebastian Ott
Cc: Marcel Apfelbaum, Michael S . Tsirkin, qemu-devel, Zhenyu Zhang
On Tue, 3 Dec 2024 13:19:28 +0100
Sebastian Ott <sebott@redhat.com> wrote:
> PCI hotplug for downstream endpoints on arm fails because Linux'
> PCIe hotplug driver doesn't like the QEMU provided LNKSTA:
>
> pcieport 0000:08:01.0: pciehp: Slot(2): Card present
> pcieport 0000:08:01.0: pciehp: Slot(2): Link Up
> pcieport 0000:08:01.0: pciehp: Slot(2): Cannot train link: status 0x2000
>
> There's 2 cases where LNKSTA isn't setup properly:
> * the downstream device has no express capability
> * max link width of the bridge is 0
>
> Move the sanity checks added via 88c869198aa63
> ("pci: Sanity test minimum downstream LNKSTA") outside of the
> branch to make sure downstream ports always have a valid LNKSTA.
>
> Signed-off-by: Sebastian Ott <sebott@redhat.com>
> Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
> ---
> hw/pci/pcie.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 0b455c8654..1b12db6fa2 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -1113,18 +1113,22 @@ void pcie_sync_bridge_lnk(PCIDevice *bridge_dev)
> if ((lnksta & PCI_EXP_LNKSTA_NLW) > (lnkcap & PCI_EXP_LNKCAP_MLW)) {
> lnksta &= ~PCI_EXP_LNKSTA_NLW;
> lnksta |= lnkcap & PCI_EXP_LNKCAP_MLW;
> - } else if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
> - lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
> }
>
> if ((lnksta & PCI_EXP_LNKSTA_CLS) > (lnkcap & PCI_EXP_LNKCAP_SLS)) {
> lnksta &= ~PCI_EXP_LNKSTA_CLS;
> lnksta |= lnkcap & PCI_EXP_LNKCAP_SLS;
> - } else if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
> - lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
> }
> }
>
> + if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
> + lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
> + }
> +
> + if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
> + lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
> + }
> +
> pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
> PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
> pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA, lnksta &
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] pci: ensure valid link status bits for downstream ports
2024-12-03 14:28 ` Alex Williamson
@ 2024-12-17 15:52 ` Sebastian Ott
2025-01-07 16:48 ` Sebastian Ott
1 sibling, 0 replies; 5+ messages in thread
From: Sebastian Ott @ 2024-12-17 15:52 UTC (permalink / raw)
To: Marcel Apfelbaum, Michael S . Tsirkin
Cc: Alex Williamson, qemu-devel, Zhenyu Zhang
Hi,
On Tue, 3 Dec 2024, Alex Williamson wrote:
> On Tue, 3 Dec 2024 13:19:28 +0100
> Sebastian Ott <sebott@redhat.com> wrote:
>
>> PCI hotplug for downstream endpoints on arm fails because Linux'
>> PCIe hotplug driver doesn't like the QEMU provided LNKSTA:
>>
>> pcieport 0000:08:01.0: pciehp: Slot(2): Card present
>> pcieport 0000:08:01.0: pciehp: Slot(2): Link Up
>> pcieport 0000:08:01.0: pciehp: Slot(2): Cannot train link: status 0x2000
>>
>> There's 2 cases where LNKSTA isn't setup properly:
>> * the downstream device has no express capability
>> * max link width of the bridge is 0
>>
>> Move the sanity checks added via 88c869198aa63
>> ("pci: Sanity test minimum downstream LNKSTA") outside of the
>> branch to make sure downstream ports always have a valid LNKSTA.
>>
>> Signed-off-by: Sebastian Ott <sebott@redhat.com>
>> Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
>> ---
>> hw/pci/pcie.c | 12 ++++++++----
>> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Can someone pick this up for the next qemu release?
Thanks,
Sebastian
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] pci: ensure valid link status bits for downstream ports
2024-12-03 14:28 ` Alex Williamson
2024-12-17 15:52 ` Sebastian Ott
@ 2025-01-07 16:48 ` Sebastian Ott
1 sibling, 0 replies; 5+ messages in thread
From: Sebastian Ott @ 2025-01-07 16:48 UTC (permalink / raw)
To: Marcel Apfelbaum, Michael S . Tsirkin
Cc: Alex Williamson, qemu-devel, Zhenyu Zhang
Hello Michael, Marcel,
On Tue, 3 Dec 2024, Alex Williamson wrote:
> On Tue, 3 Dec 2024 13:19:28 +0100
> Sebastian Ott <sebott@redhat.com> wrote:
>
>> PCI hotplug for downstream endpoints on arm fails because Linux'
>> PCIe hotplug driver doesn't like the QEMU provided LNKSTA:
>>
>> pcieport 0000:08:01.0: pciehp: Slot(2): Card present
>> pcieport 0000:08:01.0: pciehp: Slot(2): Link Up
>> pcieport 0000:08:01.0: pciehp: Slot(2): Cannot train link: status 0x2000
>>
>> There's 2 cases where LNKSTA isn't setup properly:
>> * the downstream device has no express capability
>> * max link width of the bridge is 0
>>
>> Move the sanity checks added via 88c869198aa63
>> ("pci: Sanity test minimum downstream LNKSTA") outside of the
>> branch to make sure downstream ports always have a valid LNKSTA.
>>
>> Signed-off-by: Sebastian Ott <sebott@redhat.com>
>> Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
>> ---
>> hw/pci/pcie.c | 12 ++++++++----
>> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Can you pick this up for the next qemu release, please? It fixes PCI
hotplug for downstream endpoints on arm.
Thanks,
Sebastian
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] pci: ensure valid link status bits for downstream ports
2024-12-03 12:19 [PATCH v2] pci: ensure valid link status bits for downstream ports Sebastian Ott
2024-12-03 14:28 ` Alex Williamson
@ 2025-01-17 6:21 ` Michael Tokarev
1 sibling, 0 replies; 5+ messages in thread
From: Michael Tokarev @ 2025-01-17 6:21 UTC (permalink / raw)
To: Sebastian Ott, Alex Williamson, Marcel Apfelbaum,
Michael S . Tsirkin
Cc: qemu-devel, Zhenyu Zhang, qemu-stable
03.12.2024 15:19, Sebastian Ott wrote:
> PCI hotplug for downstream endpoints on arm fails because Linux'
> PCIe hotplug driver doesn't like the QEMU provided LNKSTA:
>
> pcieport 0000:08:01.0: pciehp: Slot(2): Card present
> pcieport 0000:08:01.0: pciehp: Slot(2): Link Up
> pcieport 0000:08:01.0: pciehp: Slot(2): Cannot train link: status 0x2000
>
> There's 2 cases where LNKSTA isn't setup properly:
> * the downstream device has no express capability
> * max link width of the bridge is 0
>
> Move the sanity checks added via 88c869198aa63
> ("pci: Sanity test minimum downstream LNKSTA") outside of the
> branch to make sure downstream ports always have a valid LNKSTA.
This seems to be a qemu-stable material. Please let me know it it
is not.
Thanks,
/mjt
> Signed-off-by: Sebastian Ott <sebott@redhat.com>
> Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
> ---
> hw/pci/pcie.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 0b455c8654..1b12db6fa2 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -1113,18 +1113,22 @@ void pcie_sync_bridge_lnk(PCIDevice *bridge_dev)
> if ((lnksta & PCI_EXP_LNKSTA_NLW) > (lnkcap & PCI_EXP_LNKCAP_MLW)) {
> lnksta &= ~PCI_EXP_LNKSTA_NLW;
> lnksta |= lnkcap & PCI_EXP_LNKCAP_MLW;
> - } else if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
> - lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
> }
>
> if ((lnksta & PCI_EXP_LNKSTA_CLS) > (lnkcap & PCI_EXP_LNKCAP_SLS)) {
> lnksta &= ~PCI_EXP_LNKSTA_CLS;
> lnksta |= lnkcap & PCI_EXP_LNKCAP_SLS;
> - } else if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
> - lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
> }
> }
>
> + if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
> + lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
> + }
> +
> + if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
> + lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
> + }
> +
> pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
> PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
> pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA, lnksta &
^ permalink raw reply [flat|nested] 5+ messages in thread
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2024-12-03 12:19 [PATCH v2] pci: ensure valid link status bits for downstream ports Sebastian Ott
2024-12-03 14:28 ` Alex Williamson
2024-12-17 15:52 ` Sebastian Ott
2025-01-07 16:48 ` Sebastian Ott
2025-01-17 6:21 ` Michael Tokarev
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