On Tue, Mar 21, 2017 at 2:52 AM, Yu Zhang <yu.c.zh...@linux.intel.com> wrote: > Routine hvmemul_do_io() may need to peek the p2m type of a gfn to > select the ioreq server. For example, operations on gfns with > p2m_ioreq_server type will be delivered to a corresponding ioreq > server, and this requires that the p2m type not be switched back > to p2m_ram_rw during the emulation process. To avoid this race > condition, we delay the release of p2m lock in hvm_hap_nested_page_fault() > until mmio is handled. > > Note: previously in hvm_hap_nested_page_fault(), put_gfn() was moved > before the handling of mmio, due to a deadlock risk between the p2m > lock and the event lock(in commit 77b8dfe). Later, a per-event channel > lock was introduced in commit de6acb7, to send events. So we do not > need to worry about the deadlock issue. > > Signed-off-by: Yu Zhang <yu.c.zh...@linux.intel.com> > Reviewed-by: Jan Beulich <jbeul...@suse.com>
Who else's ack does this need? It seems like this is a general improvement that can go in without the rest of the series. -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
