On Thu, 24 Sep 2020 09:00:06 +0200 Julia Suvorova <jus...@redhat.com> 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. if I recall right, you had a idea about keeping pending removal request to distinguish between eject and poweroff (i.e. eject if mgmt asked for removal and otherwise it could be poweroff|nop) Why it didn't work out in the end? > * 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) > > 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(-) >
