On Sat, Jun 11, 2022 at 12:43:29PM -0400, Chuck Zmudzinski wrote: > In xen_pt_config_reg_init(), there is an error in the merging of the > emulated data with the host value. With the current Qemu, instead of > merging the emulated bits with the host bits as defined by emu_mask, > the emulated bits are merged with the host bits as defined by the > inverse of emu_mask. In some cases, depending on the data in the > registers on the host, the way the registers are setup, and the > initial values of the emulated bits, the end result will be that > the register is initialized with the wrong value. > > To correct this error, use the XEN_PT_MERGE_VALUE macro to help ensure > the merge is done correctly. > > This correction is needed to resolve Qemu project issue #1061, which > describes the failure of Xen HVM Linux guests to boot in certain > configurations with passed through PCI devices, that is, when this error > disables instead of enables the PCI_STATUS_CAP_LIST bit of the > PCI_STATUS register of a passed through PCI device, which in turn > disables the MSI-X capability of the device in Linux guests with the end > result being that the Linux guest never completes the boot process. > > Fixes: 2e87512eccf3 > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1061 > Buglink: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988333 > > Signed-off-by: Chuck Zmudzinski <brchu...@aol.com>
Reviewed-by: Anthony PERARD <anthony.per...@citrix.com> Thank you, looks like it's been a long quest to figure this one out. -- Anthony PERARD
