Michael S. Tsirkin writes:
> Rename function arguments to make intent clearer.
> Better documentation for slot control logic.
>
> Suggested-by: Igor Mammedov <imamm...@redhat.com>
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
> ---
>
>
> include/hw/pci/pcie.h | 3 ++-
> hw/pci/pcie.c | 17 +++++++++++------
> 2 files changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
> index 8d90c0e193..34f277735c 100644
> --- a/include/hw/pci/pcie.h
> +++ b/include/hw/pci/pcie.h
> @@ -108,7 +108,8 @@ void pcie_cap_lnkctl_reset(PCIDevice *dev);
> void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot);
> void pcie_cap_slot_reset(PCIDevice *dev);
> void pcie_cap_slot_get(PCIDevice *dev, uint16_t *slot_ctl, uint16_t
> *slt_sta);
> -void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slot_ctl, uint16_t
> slt_sta,
> +void pcie_cap_slot_write_config(PCIDevice *dev,
> + uint16_t old_slot_ctl, uint16_t old_slt_sta,
> uint32_t addr, uint32_t val, int len);
> int pcie_cap_slot_post_load(void *opaque, int version_id);
> void pcie_cap_slot_push_attention_button(PCIDevice *dev);
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index c605d32dd4..a6beb567bd 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -602,7 +602,8 @@ void pcie_cap_slot_get(PCIDevice *dev, uint16_t *slt_ctl,
> uint16_t *slt_sta)
> *slt_sta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
> }
>
> -void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slt_ctl, uint16_t
> slt_sta,
> +void pcie_cap_slot_write_config(PCIDevice *dev,
> + uint16_t old_slt_ctl, uint16_t old_slt_sta,
> uint32_t addr, uint32_t val, int len)
> {
> uint32_t pos = dev->exp.exp_cap;
> @@ -625,8 +626,8 @@ void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t
> slt_ctl, uint16_t slt_s
> PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | \
> PCI_EXP_SLTSTA_CC)
>
> - if (val & ~slt_sta & PCIE_SLOT_EVENTS) {
> - sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (slt_sta &
> PCIE_SLOT_EVENTS);
> + if (val & ~old_slt_sta & PCIE_SLOT_EVENTS) {
> + sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (old_slt_sta &
> PCIE_SLOT_EVENTS);
> pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
> }
> hotplug_event_clear(dev);
> @@ -646,13 +647,17 @@ void pcie_cap_slot_write_config(PCIDevice *dev,
> uint16_t slt_ctl, uint16_t slt_s
> }
>
> /*
> - * If the slot is polulated, power indicator is off and power
> + * If the slot is populated, power indicator is off and power
> * controller is off, it is safe to detach the devices.
> + *
> + * Note: don't detach if condition was already true:
> + * this is a work around for guests that overwrite
> + * control of powered off slots before powering them on.
> */
> if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) &&
> (val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF &&
> - (!(slt_ctl & PCI_EXP_SLTCTL_PCC) ||
> - (slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) {
> + (!(old_slt_ctl & PCI_EXP_SLTCTL_PCC) ||
> + (old_slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) {
> PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev));
> pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
> pcie_unplug_device, NULL);
Good idea.
Reviewed-by: Christophe de Dinechin <dinec...@redhat.com>
--
Cheers,
Christophe de Dinechin (IRC c3d)
