Apply patch from Jed Davis, posted to port-xen:

In pmap_remap_pages() new mappings are created (PG_RW|PG_M). When saving
a domain, the hypervisor will refuse to map the foreing pages RW.
As a temporary measure, retry the mapping read-only if PG_RW fails, so that
domain save will work. Also fix the PTP's wire_count if the MMU update
fails (prevent a kernel panic).
This commit is contained in:
bouyer 2005-09-10 15:46:04 +00:00
parent 7558bd0a7c
commit 8dfe5bc813
1 changed files with 30 additions and 5 deletions

View File

@ -1,4 +1,4 @@
/* $NetBSD: pmap.c,v 1.12 2005/05/29 15:57:02 chs Exp $ */
/* $NetBSD: pmap.c,v 1.13 2005/09/10 15:46:04 bouyer Exp $ */
/* NetBSD: pmap.c,v 1.179 2004/10/10 09:55:24 yamt Exp */
/*
@ -61,7 +61,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.12 2005/05/29 15:57:02 chs Exp $");
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.13 2005/09/10 15:46:04 bouyer Exp $");
#include "opt_cputype.h"
#include "opt_user_ldt.h"
@ -4064,7 +4064,9 @@ pmap_remap_pages(pmap, va, pa, npages, flags, dom)
struct vm_page_md *mdpg;
struct pv_head *old_pvh;
struct pv_entry *pve = NULL; /* XXX gcc */
int error;
int error, dptpwire;
dptpwire = 0;
XENPRINTK(("pmap_remap_pages(%p, %p, %p, %d, %08x, %d)\n",
pmap, (void *)va, (void *)pa, npages, flags, dom));
@ -4230,14 +4232,37 @@ pmap_remap_pages(pmap, va, pa, npages, flags, dom)
} else {
pmap->pm_stats.resident_count++;
pmap->pm_stats.wired_count++;
if (ptp)
if (ptp) {
dptpwire = 1;
ptp->wire_count++;
}
}
//printf("pmap initial setup");
maptp = (pt_entry_t *)vtomach((vaddr_t)&ptes[x86_btop(va)]);
change_pte:
error = xpq_update_foreign(maptp, npte, dom);
if (error) {
if (npte & PG_RW) {
/*
* XXXjld@panix.com: Some things cannot be
* mapped read/write, even by a privileged
* domain. This wouldn't be necessary if
* pmap_remap_pages had a "prot" parameter
* like pmap_enter does.
*/
npte &= ~(PG_RW | PG_M);
//printf("pmap_remap_pages: losing write bit npte=%lx\n", (unsigned long)npte);
goto change_pte;
}
printf("pmap_remap_pages: xpq_update_foreign failed va=%lx"
" npte=%lx error=%d dptpwire=%d\n",
va, (unsigned long)npte, error, dptpwire);
ptp->wire_count -= dptpwire;
/* XXX fix other stats? */
goto out;
}
shootdown_test:
/* Update page attributes if needed */
if ((opte & (PG_V | PG_U)) == (PG_V | PG_U)) {