search for: guest_io_read

...alue gets masked to the read width when merging back into the full result, setting the initial value to all ones should not harm any or the other cases. Signed-off-by: Jan Beulich <jbeulich@suse.com> --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -1717,7 +1717,7 @@ static uint32_t guest_io_read( while ( bytes != 0 ) { unsigned int size = 1; - uint32_t sub_data = 0xff; + uint32_t sub_data = ~0; if ( (port == 0x42) || (port == 0x43) || (port == 0x61) ) { _______________________________________________ Xen-devel mailing list Xen-devel...

...eading logic Hardware support. - x86/cpuidle: deny access to the I/O port used for EM_SYSIO - xen: Fix schedule()'s grabbing of the schedule lock - SVM: fix performance decrease with asid assignment - x86/mm: fix mod_l1_entry() return value when encountering r/o MMIO page - x86/PCI: fix guest_io_read() when pci_cfg_ok() denies access - passthrough: fix xsm-related oversight Bastian -- A father doesn't destroy his children. -- Lt. Carolyn Palamas, "Who Mourns for Adonais?", stardate 3468.1.

...to go without interception that Xen doesn''t need to do any internal state keeping on (and of course also only for those the guest is allowed to access). That would make - for PVH - unnecessary a significant part of emulate_privileged_op(): In essence, all you''d need to wire up are guest_io_read() and guest_io_write(). In particular it would then hopefully be safe to do all that without the on-stack emulation stub, as this ought to be necessary only for Dom0, which ought to always have direct access to such "special" I/O ports. With one apparent caveat: SVM sets GENERAL1_INTERCE...