[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH RFC V2 6/6] xen: Handle resumed instruction based on previous mem_event reply
On 11/07/14 16:43, Razvan Cojocaru wrote: > In a scenario where a page fault that triggered a mem_event occured, > p2m_mem_access_check() will now be able to either 1) emulate the > current instruction, or 2) emulate it, but don't allow it to perform > any writes. > > Changes since V1: > - Removed the 'skip' code which required computing the current > instruction length. > - Removed the set_ad_bits() code that attempted to modify the > 'accessed' and 'dirty' bits for instructions that the emulator > can't handle at the moment. > > Signed-off-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx> > --- > xen/arch/x86/domain.c | 5 +++ > xen/arch/x86/mm/p2m.c | 90 > ++++++++++++++++++++++++++++++++++++++++ > xen/include/asm-x86/domain.h | 9 ++++ > xen/include/public/mem_event.h | 12 +++--- > 4 files changed, 111 insertions(+), 5 deletions(-) > > diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c > index e896210..5cd283b 100644 > --- a/xen/arch/x86/domain.c > +++ b/xen/arch/x86/domain.c > @@ -407,6 +407,11 @@ int vcpu_initialise(struct vcpu *v) > > v->arch.flags = TF_kernel_mode; > > + /* By default, do not emulate */ > + v->arch.mem_event.emulate_flags = 0; > + v->arch.mem_event.gpa = 0; > + v->arch.mem_event.eip = 0; > + > rc = mapcache_vcpu_init(v); > if ( rc ) > return rc; > diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c > index 13fdf78..7aff480 100644 > --- a/xen/arch/x86/mm/p2m.c > +++ b/xen/arch/x86/mm/p2m.c > @@ -1377,6 +1377,7 @@ bool_t p2m_mem_access_check(paddr_t gpa, bool_t > gla_valid, unsigned long gla, > { > struct vcpu *v = current; > unsigned long gfn = gpa >> PAGE_SHIFT; > + unsigned long exit_qualification; > struct domain *d = v->domain; > struct p2m_domain* p2m = p2m_get_hostp2m(d); > mfn_t mfn; > @@ -1384,6 +1385,9 @@ bool_t p2m_mem_access_check(paddr_t gpa, bool_t > gla_valid, unsigned long gla, > p2m_access_t p2ma; > mem_event_request_t *req; > int rc; > + unsigned long eip = guest_cpu_user_regs()->eip; > + > + __vmread(EXIT_QUALIFICATION, &exit_qualification); This absolutely can't be put into common code. I presume you haven't attempted to run a Xen patched with this on an AMD cpu ? ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |