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Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug
From: |
Igor Mammedov |
Subject: |
Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus |
Date: |
Thu, 27 Aug 2020 19:41:15 +0200 |
On Thu, 27 Aug 2020 09:40:34 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:
> From: Ani Sinha <ani@anisinha.ca>
>
> We introduce a new global flag 'acpi-root-pci-hotplug' for i440fx with which
> we can turn on or off PCI device hotplug on the root bus. This flag can be
> used to prevent all PCI devices from getting hotplugged or unplugged from the
> root PCI bus.
> This feature is targetted mostly towards Windows VMs. It is useful in cases
> where some hypervisor admins want to deploy guest VMs in a way so that the
> users of the guest OSes are not able to hot-eject certain PCI devices from
> the Windows system tray. Laine has explained the use case here in detail:
> https://www.redhat.com/archives/libvir-list/2020-February/msg00110.html
>
> Julia has resolved this issue for PCIE buses with the following commit:
> 530a0963184e57e71a5b538 ("pcie_root_port: Add hotplug disabling option")
>
> This commit attempts to introduce similar behavior for PCI root buses used in
> i440fx machine types (although in this case, we do not have a per-slot
> capability to turn hotplug on or off).
>
> Usage:
> -global PIIX4_PM.acpi-root-pci-hotplug=off
>
> By default, this option is enabled which means that hotplug is turned on for
> the PCI root bus.
>
> The previously existing flag 'acpi-pci-hotplug-with-bridge-support' for
> PCI-PCI
> bridges remain as is and can be used along with this new flag to control PCI
> hotplug on PCI bridges.
>
> This change has been tested using a Windows 2012R2 server guest image and also
> with a Windows 2019 server guest image on a Ubuntu 18.04 host using the latest
> master qemu from upstream.
>
> Signed-off-by: Ani Sinha <ani@anisinha.ca>
> Message-Id: <20200821165403.26589-1-ani@anisinha.ca>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Tested-by: Igor Mammedov <imammedo@redhat.com>
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
A glitch in scripts?
I didn't review nor tested this (v8) version
> ---
> include/hw/acpi/pcihp.h | 2 +-
> hw/acpi/pcihp.c | 23 ++++++++++++++++++++++-
> hw/acpi/piix4.c | 5 ++++-
> 3 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/include/hw/acpi/pcihp.h b/include/hw/acpi/pcihp.h
> index 8bc4a4c01d..02f4665767 100644
> --- a/include/hw/acpi/pcihp.h
> +++ b/include/hw/acpi/pcihp.h
> @@ -67,7 +67,7 @@ void acpi_pcihp_device_unplug_request_cb(HotplugHandler
> *hotplug_dev,
> Error **errp);
>
> /* Called on reset */
> -void acpi_pcihp_reset(AcpiPciHpState *s);
> +void acpi_pcihp_reset(AcpiPciHpState *s, bool acpihp_root_off);
>
> extern const VMStateDescription vmstate_acpi_pcihp_pci_status;
>
> diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
> index 9e31ab2da4..39b1f74442 100644
> --- a/hw/acpi/pcihp.c
> +++ b/hw/acpi/pcihp.c
> @@ -104,6 +104,24 @@ static void acpi_set_pci_info(void)
> }
> }
>
> +static void acpi_pcihp_disable_root_bus(void)
> +{
> + static bool root_hp_disabled;
> + PCIBus *bus;
> +
> + if (root_hp_disabled) {
> + return;
> + }
> +
> + bus = find_i440fx();
> + if (bus) {
> + /* setting the hotplug handler to NULL makes the bus
> non-hotpluggable */
> + qbus_set_hotplug_handler(BUS(bus), NULL);
> + }
> + root_hp_disabled = true;
> + return;
> +}
> +
> static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
> {
> AcpiPciHpFind *find = opaque;
> @@ -209,8 +227,11 @@ static void acpi_pcihp_update(AcpiPciHpState *s)
> }
> }
>
> -void acpi_pcihp_reset(AcpiPciHpState *s)
> +void acpi_pcihp_reset(AcpiPciHpState *s, bool acpihp_root_off)
> {
> + if (acpihp_root_off) {
> + acpi_pcihp_disable_root_bus();
> + }
> acpi_set_pci_info();
> acpi_pcihp_update(s);
> }
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index 26bac4f16c..e6163bb6ce 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -78,6 +78,7 @@ typedef struct PIIX4PMState {
>
> AcpiPciHpState acpi_pci_hotplug;
> bool use_acpi_hotplug_bridge;
> + bool use_acpi_root_pci_hotplug;
>
> uint8_t disable_s3;
> uint8_t disable_s4;
> @@ -324,7 +325,7 @@ static void piix4_pm_reset(DeviceState *dev)
> pci_conf[0x5B] = 0x02;
> }
> pm_io_space_update(s);
> - acpi_pcihp_reset(&s->acpi_pci_hotplug);
> + acpi_pcihp_reset(&s->acpi_pci_hotplug, !s->use_acpi_root_pci_hotplug);
> }
>
> static void piix4_pm_powerdown_req(Notifier *n, void *opaque)
> @@ -635,6 +636,8 @@ static Property piix4_pm_properties[] = {
> DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_VAL, PIIX4PMState, s4_val, 2),
> DEFINE_PROP_BOOL("acpi-pci-hotplug-with-bridge-support", PIIX4PMState,
> use_acpi_hotplug_bridge, true),
> + DEFINE_PROP_BOOL("acpi-root-pci-hotplug", PIIX4PMState,
> + use_acpi_root_pci_hotplug, true),
> DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
> acpi_memory_hotplug.is_enabled, true),
> DEFINE_PROP_END_OF_LIST(),
- [PULL 00/13] virtio,pc,acpi: features, fixes, Michael S. Tsirkin, 2020/08/27
- [PULL 01/13] acpi: allow DSDT changes, Michael S. Tsirkin, 2020/08/27
- [PULL 02/13] i386/acpi: fix inconsistent QEMU/OVMF device paths, Michael S. Tsirkin, 2020/08/27
- [PULL 03/13] arm/acpi: fix an out of spec _UID for PCI root, Michael S. Tsirkin, 2020/08/27
- [PULL 04/13] disassemble-aml: -o actually works, Michael S. Tsirkin, 2020/08/27
- [PULL 05/13] acpi: update expected DSDT files with _UID changes, Michael S. Tsirkin, 2020/08/27
- [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Michael S. Tsirkin, 2020/08/27
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus,
Igor Mammedov <=
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Ani Sinha, 2020/08/27
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Igor Mammedov, 2020/08/28
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Ani Sinha, 2020/08/28
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Julia Suvorova, 2020/08/28
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Ani Sinha, 2020/08/28
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Julia Suvorova, 2020/08/28
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Ani Sinha, 2020/08/30
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Michael S. Tsirkin, 2020/08/30
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Ani Sinha, 2020/08/31
- Re: [PULL 06/13] Introduce a new flag for i440fx to disable PCI hotplug on the root bus, Michael S. Tsirkin, 2020/08/30