On Thu, Sep 24, 2020 at 11:20 AM Michael S. Tsirkin <m...@redhat.com> wrote: > > On Thu, Sep 24, 2020 at 09:00:06AM +0200, Julia Suvorova wrote: > > The patch set consists of two parts: > > patches 1-4: introduce new feature > > 'acpi-pci-hotplug-with-bridge-support' on Q35 > > patches 5-7: make the feature default along with changes in ACPI tables > > > > This way maintainers can decide which way to choose without breaking > > the patch set. > > > > With the feature disabled Q35 falls back to the native hot-plug. > > > > Pros > > * no racy behavior during boot (see 110c477c2ed) > > * eject is possible - according to PCIe spec, attention button > > press should lead to power off, and then the adapter should be > > removed manually. As there is no power down state exists in QEMU, > > we cannot distinguish between an eject and a power down > > request. > > * no delay during deleting - after the actual power off software > > must wait at least 1 second before indicating about it. This case > > is quite important for users, it even has its own bug: > > https://bugzilla.redhat.com/show_bug.cgi?id=1594168 > > * no timer-based behavior - in addition to the previous example, > > the attention button has a 5-second waiting period, during which > > the operation can be canceled with a second press. While this > > looks fine for manual button control, automation will result in > > the need to queue or drop events, and the software receiving > > events in all sort of unspecified combinations of attention/power > > indicator states, which is racy and uppredictable. > > * fixes: > > * https://bugzilla.redhat.com/show_bug.cgi?id=1752465 > > * https://bugzilla.redhat.com/show_bug.cgi?id=1690256 > > > > Cons: > > * lose per-port control over hot-plug (can be resolved) > > * no access to possible features presented in slot capabilities > > (this is only surprise removal AFAIK) > > something I don't quite get is whether with this one can still add > new pcie bridges and then hotplug into these with native > hotplug.
Right now I disable native if there is acpihp anywhere, but even if you enable it for hotplugged devices, native hot-plug will not work. > the challenge to answering this with certainty is that right now qemu > does not allow hotplugging complex devices such as bridges at all, > we only have a hack for multifunction devices. > Maybe adding a bridge as function 1 on command line, then hotplugging another > device as > function 0 will work to test this. > > > > > v3: > > * drop change of _OSC to allow SHPC on hotplugged bridges > > * use 'acpi-root-pci-hotplug' > > * add migration states [Igor] > > * minor style changes > > > > v2: > > * new ioport range for acpiphp [Gerd] > > * drop find_pci_host() [Igor] > > * explain magic numbers in _OSC [Igor] > > * drop build_q35_pci_hotplug() wrapper [Igor] > > > > Julia Suvorova (7): > > hw/acpi/pcihp: Enhance acpi_pcihp_disable_root_bus() to support Q35 > > hw/i386/acpi-build: Add ACPI PCI hot-plug methods to Q35 > > hw/pci/pcie: Do not initialize slot capability if acpihp is used > > hw/acpi/ich9: Enable ACPI PCI hot-plug > > bios-tables-test: Allow changes in DSDT ACPI tables > > hw/acpi/ich9: Set ACPI PCI hot-plug as default > > bios-tables-test: Update golden binaries > > > > hw/i386/acpi-build.h | 7 ++++ > > include/hw/acpi/ich9.h | 5 +++ > > include/hw/acpi/pcihp.h | 3 +- > > hw/acpi/ich9.c | 67 ++++++++++++++++++++++++++++++ > > hw/acpi/pcihp.c | 16 ++++--- > > hw/acpi/piix4.c | 4 +- > > hw/i386/acpi-build.c | 31 ++++++++------ > > hw/i386/pc.c | 1 + > > hw/pci/pcie.c | 16 +++++++ > > tests/data/acpi/q35/DSDT | Bin 7678 -> 7950 bytes > > tests/data/acpi/q35/DSDT.acpihmat | Bin 9002 -> 9274 bytes > > tests/data/acpi/q35/DSDT.bridge | Bin 7695 -> 9865 bytes > > tests/data/acpi/q35/DSDT.cphp | Bin 8141 -> 8413 bytes > > tests/data/acpi/q35/DSDT.dimmpxm | Bin 9331 -> 9603 bytes > > tests/data/acpi/q35/DSDT.ipmibt | Bin 7753 -> 8025 bytes > > tests/data/acpi/q35/DSDT.memhp | Bin 9037 -> 9309 bytes > > tests/data/acpi/q35/DSDT.mmio64 | Bin 8808 -> 9080 bytes > > tests/data/acpi/q35/DSDT.numamem | Bin 7684 -> 7956 bytes > > tests/data/acpi/q35/DSDT.tis | Bin 8283 -> 8555 bytes > > 19 files changed, 129 insertions(+), 21 deletions(-) > > > > -- > > 2.25.4 >
