[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 1/2] xen: Drop XEN_DOMCTL_suppress_spurious_page_faults

On 13.08.2019 12:53, Andrew Cooper wrote:
This functionality is obsolete.  It was introduced by c/s 39407bed9c0 into
Xend, but never exposed in libxl.

This is good enough a reason I think (hope), while ...

While not explicitly limited to PV guests, this is PV-only by virtue of its
position in the pagefault handler.

Looking though the XenServer templates, this was used to work around bugs in
the 32bit RHEL/CentOS 4.{5..7} kernels (fixed in 4.8).  RHEL 4 as a major
version when out if support in 2017.

... I wouldn't accept this as justification, since people are
free to use out-of-support software for as long as they wish.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Hypervisor parts
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
with one further suggestion:

--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1452,20 +1452,6 @@ void do_page_fault(struct cpu_user_regs *regs)
                error_code, _p(addr));
- if ( unlikely(current->domain->arch.suppress_spurious_page_faults) )
-    {
-        pf_type = spurious_page_fault(addr, regs);
-        if ( (pf_type == smep_fault) || (pf_type == smap_fault))
-        {
-            printk(XENLOG_G_ERR "%pv fatal SM%cP violation\n",
-                   current, (pf_type == smep_fault) ? 'E' : 'A');
-            domain_crash(current->domain);
-        }
-        if ( pf_type != real_fault )
-            return;
-    }

You may want to consider reducing pf_type's scope at the same


Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.