From: Gerd Hoffmann <kraxel@redhat.com>
To: Ani Sinha <ani@anisinha.ca>
Cc: Gregory Price <gourry.memverge@gmail.com>,
qemu-devel@nongnu.org, mst@redhat.com,
marcel.apfelbaum@gmail.com, imammedo@redhat.com,
jonathan.cameron@huawei.com, linux-cxl@vger.kernel.org,
alison.schofield@intel.com, dave@stgolabs.net,
a.manzanares@samsung.com, bwidawsk@kernel.org,
gregory.price@memverge.com, hchkuo@avery-design.com.tw,
cbrowy@avery-design.com, ira.weiny@intel.com
Subject: Re: [BUG] hw/i386/pc.c: CXL Fixed Memory Window should not reserve e820 in bios
Date: Tue, 8 Nov 2022 12:21:11 +0100 [thread overview]
Message-ID: <20221108112111.czqldmb7wemhqy6f@sirius.home.kraxel.org> (raw)
In-Reply-To: <CAARzgwyCTaNoiqtVPS394Nk9LAS05116Dvc2GxifHpO01+ZN4g@mail.gmail.com>
> >> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> >> > index 566accf7e6..5bf5465a21 100644
> >> > --- a/hw/i386/pc.c
> >> > +++ b/hw/i386/pc.c
> >> > @@ -1061,7 +1061,6 @@ void pc_memory_init(PCMachineState *pcms,
> >> > hwaddr cxl_size = MiB;
> >> >
> >> > cxl_base = pc_get_cxl_range_start(pcms);
> >> > - e820_add_entry(cxl_base, cxl_size, E820_RESERVED);
Just dropping it doesn't look like a good plan to me.
You can try set etc/reserved-memory-end fw_cfg file instead. Firmware
(both seabios and ovmf) read it and will make sure the 64bit pci mmio
window is placed above that address, i.e. this effectively reserves
address space. Right now used by memory hotplug code, but should work
for cxl too I think (disclaimer: don't know much about cxl ...).
take care & HTH,
Gerd
next prev parent reply other threads:[~2022-11-08 11:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-17 23:40 [BUG] hw/i386/pc.c: CXL Fixed Memory Window should not reserve e820 in bios Gregory Price
2022-10-18 2:58 ` Gupta, Pankaj
2022-10-18 14:49 ` Gregory Price
2022-10-18 6:05 ` Ani Sinha
2022-10-18 14:45 ` Gregory Price
2022-10-18 15:00 ` Ani Sinha
2022-11-08 11:21 ` Gerd Hoffmann [this message]
2022-11-11 10:51 ` Igor Mammedov
2022-11-11 11:40 ` Gerd Hoffmann
2022-11-11 13:24 ` Igor Mammedov
2022-11-11 13:36 ` Gerd Hoffmann
2022-11-11 14:37 ` Michael S. Tsirkin
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