| Message ID | d814a518fc201c76ffd8f254c534719ee278175a.1576697796.git.tamas.lengyel@intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | VM forking | expand |
On 18.12.2019 21:40, Tamas K Lengyel wrote: > Use __get_gfn_type_access instead of p2m->get_entry to trigger page-forking > when the mem_access permission is being set on a page that has not yet been > copied over from the parent. > > Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.comReviewed-by: Alexandru Isaila <aisaila@bitdefender.com> > --- > xen/arch/x86/mm/mem_access.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c > index 320b9fe621..9caf08a5b2 100644 > --- a/xen/arch/x86/mm/mem_access.c > +++ b/xen/arch/x86/mm/mem_access.c > @@ -303,11 +303,10 @@ static int set_mem_access(struct domain *d, struct p2m_domain *p2m, > ASSERT(!ap2m); > #endif > { > - mfn_t mfn; > p2m_access_t _a; > p2m_type_t t; > - > - mfn = p2m->get_entry(p2m, gfn, &t, &_a, 0, NULL, NULL); > + mfn_t mfn = __get_gfn_type_access(p2m, gfn_x(gfn), &t, &_a, > + P2M_ALLOC, NULL, false); Don't you want p2m_query_t to be 0 as it was in the p2m->get_entry() call ? > rc = p2m->set_entry(p2m, gfn, mfn, PAGE_ORDER_4K, t, a, -1); > } > > Alex
On Thu, Dec 19, 2019 at 12:59 AM Alexandru Stefan ISAILA <aisaila@bitdefender.com> wrote: > > > > On 18.12.2019 21:40, Tamas K Lengyel wrote: > > Use __get_gfn_type_access instead of p2m->get_entry to trigger page-forking > > when the mem_access permission is being set on a page that has not yet been > > copied over from the parent. > > > > Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.comReviewed-by: Alexandru Isaila <aisaila@bitdefender.com> > > > --- > > xen/arch/x86/mm/mem_access.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c > > index 320b9fe621..9caf08a5b2 100644 > > --- a/xen/arch/x86/mm/mem_access.c > > +++ b/xen/arch/x86/mm/mem_access.c > > @@ -303,11 +303,10 @@ static int set_mem_access(struct domain *d, struct p2m_domain *p2m, > > ASSERT(!ap2m); > > #endif > > { > > - mfn_t mfn; > > p2m_access_t _a; > > p2m_type_t t; > > - > > - mfn = p2m->get_entry(p2m, gfn, &t, &_a, 0, NULL, NULL); > > + mfn_t mfn = __get_gfn_type_access(p2m, gfn_x(gfn), &t, &_a, > > + P2M_ALLOC, NULL, false); > > Don't you want p2m_query_t to be 0 as it was in the p2m->get_entry() call ? No, the entire point of the patch is to have the P2M_ALLOC query flag set. That triggers the fork's p2m population. Tamas
diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c index 320b9fe621..9caf08a5b2 100644 --- a/xen/arch/x86/mm/mem_access.c +++ b/xen/arch/x86/mm/mem_access.c @@ -303,11 +303,10 @@ static int set_mem_access(struct domain *d, struct p2m_domain *p2m, ASSERT(!ap2m); #endif { - mfn_t mfn; p2m_access_t _a; p2m_type_t t; - - mfn = p2m->get_entry(p2m, gfn, &t, &_a, 0, NULL, NULL); + mfn_t mfn = __get_gfn_type_access(p2m, gfn_x(gfn), &t, &_a, + P2M_ALLOC, NULL, false); rc = p2m->set_entry(p2m, gfn, mfn, PAGE_ORDER_4K, t, a, -1); }
Use __get_gfn_type_access instead of p2m->get_entry to trigger page-forking when the mem_access permission is being set on a page that has not yet been copied over from the parent. Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com> --- xen/arch/x86/mm/mem_access.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)