[PATCH 0/1] OvmfPkg/Bhyve: QemuFwCfg support

["Corvin Köhne" <c.koehne@beckhoff.com>]

Hi,

I'm going to add QemuFwCfg support to bhyve. See
https://reviews.freebsd.org/D31578. Therefore, this patch for OVMF is
neccessary to work properly.

There's one open point on that patch and hopefully one of you has more
insights. Qemu has an item called FW_CFG_MAX_CPUS. It looks very similar to
what we need here, but I'm not sure if we can use it safely as Qemu has a
comment about it:

https://github.com/qemu/qemu/blob/0021c4765a6b83e5b09409b75d50c6caaa6971b9/hw/i386/fw_cfg.c#L110-L121

    /* FW_CFG_MAX_CPUS is a bit confusing/problematic on x86:
     *
     * For machine types prior to 1.8, SeaBIOS needs FW_CFG_MAX_CPUS for
     * building MPTable, ACPI MADT, ACPI CPU hotplug and ACPI SRAT table,
     * that tables are based on xAPIC ID and QEMU<->SeaBIOS interface
     * for CPU hotplug also uses APIC ID and not "CPU index".
     * This means that FW_CFG_MAX_CPUS is not the "maximum number of CPUs",
     * but the "limit to the APIC ID values SeaBIOS may see".
     *
     * So for compatibility reasons with old BIOSes we are stuck with
     * "etc/max-cpus" actually being apic_id_limit
     */


Thanks
Corvin

CC: Ard Biesheuvel <ardb+tianocore@kernel.org>
CC: Jiewen Yao <jiewen.yao@intel.com>
CC: Jordan Justen <jordan.l.justen@intel.com>
CC: Gerd Hoffmann <kraxel@redhat.com>
CC: Rebecca Cran <rebecca@bsdio.com>
CC: Peter Grehan <grehan@freebsd.org>
CC: devel@edk2.groups.io
CC: FreeBSD Virtualization <freebsd-virtualization@freebsd.org>

Corvin Köhne (1):
  OvmfPkg/BhyveBhfPkg: add support for QemuFwCfg

 OvmfPkg/Bhyve/AcpiPlatformDxe/AcpiPlatformDxe.inf |  1 +
 OvmfPkg/Bhyve/AcpiPlatformDxe/Bhyve.c             | 41 ++++++++++++++++++++---
 OvmfPkg/Bhyve/BhyveX64.dsc                        |  4 +--
 3 files changed, 40 insertions(+), 6 deletions(-)

-- 
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