On Thu, May 13, 2021 at 08:26:35AM +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.
This is in good shape, I think the next version can be a non-RFC series. > 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 or reduces the likelihood of the bugs: > * https://bugzilla.redhat.com/show_bug.cgi?id=1833187 > * https://bugzilla.redhat.com/show_bug.cgi?id=1657077 > * https://bugzilla.redhat.com/show_bug.cgi?id=1669931 > * https://bugzilla.redhat.com/show_bug.cgi?id=1678290 > > Cons: > * no access to possible features presented in slot capabilities > (this is only surprise removal AFAIK) > > v4: > * regain per-port control over hot-plug > * rebased over acpi-index changes > * set property on machine type to > make pci code more generic [Igor, Michael] > > 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/acpi/ich9: Enable ACPI PCI hot-plug > hw/pci/pcie: Do not set HPC flag if acpihp is used > bios-tables-test: Allow changes in DSDT ACPI tables > hw/acpi/ich9: Set ACPI PCI hot-plug as default on Q35 > bios-tables-test: Update golden binaries > > hw/i386/acpi-build.h | 5 +++ > include/hw/acpi/ich9.h | 5 +++ > include/hw/acpi/pcihp.h | 3 +- > include/hw/boards.h | 1 + > hw/acpi/ich9.c | 68 ++++++++++++++++++++++++++++++ > hw/acpi/pcihp.c | 22 +++++++--- > hw/acpi/piix4.c | 4 +- > hw/core/machine.c | 19 +++++++++ > hw/i386/acpi-build.c | 32 ++++++++------ > hw/i386/pc.c | 4 +- > hw/i386/pc_q35.c | 8 ++++ > hw/pci/pcie.c | 11 ++++- > tests/data/acpi/q35/DSDT | Bin 7859 -> 8289 bytes > tests/data/acpi/q35/DSDT.acpihmat | Bin 9184 -> 9614 bytes > tests/data/acpi/q35/DSDT.bridge | Bin 7877 -> 11003 bytes > tests/data/acpi/q35/DSDT.cphp | Bin 8323 -> 8753 bytes > tests/data/acpi/q35/DSDT.dimmpxm | Bin 9513 -> 9943 bytes > tests/data/acpi/q35/DSDT.ipmibt | Bin 7934 -> 8364 bytes > tests/data/acpi/q35/DSDT.memhp | Bin 9218 -> 9648 bytes > tests/data/acpi/q35/DSDT.mmio64 | Bin 8990 -> 9419 bytes > tests/data/acpi/q35/DSDT.nohpet | Bin 7717 -> 8147 bytes > tests/data/acpi/q35/DSDT.numamem | Bin 7865 -> 8295 bytes > tests/data/acpi/q35/DSDT.tis | Bin 8465 -> 8894 bytes > 23 files changed, 161 insertions(+), 21 deletions(-) > > -- > 2.30.2
