On Mon, Jun 24, 2024 at 11:01:09AM +0200, Gerd Hoffmann wrote:
> This patch changes the logic added by commit a6ed6b701f0a ("limit
> address space used for pci devices.") a bit. Further testing showed
> that the limit of 46 phys-bits applies to x86_64 kernels only, for i386
> kernels the limit is 44. So change the limit from 46 to 44 for better
> compatibility with i386 guests.
>
> Also add one more condition to refine the configuration heuristic:
> Apply the limit only in case the guest has less than 1 TB of memory
> installed, so huge guests run without address space limits.
Thanks. Looks good to me.
Reviewed-by: Kevin O'Connor <ke...@koconnor.net>
-Kevin
>
> Signed-off-by: Gerd Hoffmann <kra...@redhat.com>
> ---
> src/fw/pciinit.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
> index bb44dc296047..b3e359d7fe62 100644
> --- a/src/fw/pciinit.c
> +++ b/src/fw/pciinit.c
> @@ -1189,11 +1189,16 @@ pci_setup(void)
>
> if (CPUPhysBits) {
> pci_mem64_top = 1LL << CPUPhysBits;
> - if (CPUPhysBits > 46) {
> - // Old linux kernels have trouble dealing with more than 46
> - // phys-bits, so avoid that for now. Seems to be a bug in the
> - // virtio-pci driver. Reported: centos-7, ubuntu-18.04
> - pci_mem64_top = 1LL << 46;
> + if (CPUPhysBits > 44) {
> + // Old linux kernels have trouble dealing with more than 44 (i386
> + // kernels) or 46 (x86_64 kernels) phys-bits. Seems to be a bug
> in
> + // the virtio-pci driver.
> + // Reported: centos-7, ubuntu-18.04
> + // Limit the used address space to mitigate the bug, except we
> are
> + // running in a huge guest with more than 1TB of memory
> installed.
> + if (RamSizeOver4G < (1LL << 40)) {
> + pci_mem64_top = 1LL << 44;
> + }
> }
> }
>
> --
> 2.45.2
>
> _______________________________________________
> SeaBIOS mailing list -- seabios@seabios.org
> To unsubscribe send an email to seabios-le...@seabios.org
_______________________________________________
SeaBIOS mailing list -- seabios@seabios.org
To unsubscribe send an email to seabios-le...@seabios.org
