>From: George Dunlap [mailto:george.dun...@citrix.com] >Sent: Tuesday, July 21, 2015 6:19 AM > >On 07/21/2015 12:58 AM, Ed White wrote: >> Add the remaining routines required to support enabling the alternate >> p2m functionality. >> >> Signed-off-by: Ed White <edmund.h.wh...@intel.com> >> >> Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com> >> --- >> xen/arch/x86/hvm/hvm.c | 58 +++++- >> xen/arch/x86/mm/hap/Makefile | 1 + >> xen/arch/x86/mm/hap/altp2m_hap.c | 98 ++++++++++ >> xen/arch/x86/mm/p2m-ept.c | 3 + >> xen/arch/x86/mm/p2m.c | 385 >+++++++++++++++++++++++++++++++++++++++ >> xen/include/asm-x86/hvm/altp2m.h | 4 + >> xen/include/asm-x86/p2m.h | 33 ++++ >> 7 files changed, 576 insertions(+), 6 deletions(-) create mode >> 100644 xen/arch/x86/mm/hap/altp2m_hap.c >> >> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index >> f0ab4d4..38cf0c6 100644 >> --- a/xen/arch/x86/hvm/hvm.c >> +++ b/xen/arch/x86/hvm/hvm.c >> @@ -2856,10 +2856,11 @@ int hvm_hap_nested_page_fault(paddr_t gpa, >unsigned long gla, >> mfn_t mfn; >> struct vcpu *curr = current; >> struct domain *currd = curr->domain; >> - struct p2m_domain *p2m; >> + struct p2m_domain *p2m, *hostp2m; >> int rc, fall_through = 0, paged = 0; >> int sharing_enomem = 0; >> vm_event_request_t *req_ptr = NULL; >> + bool_t ap2m_active = 0; >> >> /* On Nested Virtualization, walk the guest page table. >> * If this succeeds, all is fine. >> @@ -2919,11 +2920,31 @@ int hvm_hap_nested_page_fault(paddr_t gpa, >unsigned long gla, >> goto out; >> } >> >> - p2m = p2m_get_hostp2m(currd); >> - mfn = get_gfn_type_access(p2m, gfn, &p2mt, &p2ma, >> + ap2m_active = altp2m_active(currd); >> + >> + /* Take a lock on the host p2m speculatively, to avoid potential >> + * locking order problems later and to handle unshare etc. >> + */ >> + hostp2m = p2m_get_hostp2m(currd); >> + mfn = get_gfn_type_access(hostp2m, gfn, &p2mt, &p2ma, >> P2M_ALLOC | (npfec.write_access ? P2M_UNSHARE >> : 0), >> NULL); >> >> + if ( ap2m_active ) >> + { >> + if ( altp2m_hap_nested_page_fault(curr, gpa, gla, npfec, &p2m) == 1 >> ) >> + { >> + /* entry was lazily copied from host -- retry */ >> + __put_gfn(hostp2m, gfn); >> + rc = 1; >> + goto out; >> + } >> + >> + mfn = get_gfn_type_access(p2m, gfn, &p2mt, &p2ma, 0, NULL); >> + } >> + else >> + p2m = hostp2m; >> + >> /* Check access permissions first, then handle faults */ >> if ( mfn_x(mfn) != INVALID_MFN ) >> { >> @@ -2963,6 +2984,20 @@ int hvm_hap_nested_page_fault(paddr_t gpa, >> unsigned long gla, >> >> if ( violation ) >> { >> + /* Should #VE be emulated for this fault? */ >> + if ( p2m_is_altp2m(p2m) && !cpu_has_vmx_virt_exceptions ) >> + { >> + bool_t sve; >> + >> + p2m->get_entry(p2m, gfn, &p2mt, &p2ma, 0, NULL, >> + &sve); >> + >> + if ( !sve && altp2m_vcpu_emulate_ve(curr) ) >> + { >> + rc = 1; >> + goto out_put_gfn; >> + } >> + } >> + >> if ( p2m_mem_access_check(gpa, gla, npfec, &req_ptr) ) >> { >> fall_through = 1; >> @@ -2982,7 +3017,9 @@ int hvm_hap_nested_page_fault(paddr_t gpa, >unsigned long gla, >> (npfec.write_access && >> (p2m_is_discard_write(p2mt) || (p2mt == p2m_mmio_write_dm))) ) >> { >> - put_gfn(currd, gfn); >> + __put_gfn(p2m, gfn); >> + if ( ap2m_active ) >> + __put_gfn(hostp2m, gfn); >> >> rc = 0; >> if ( unlikely(is_pvh_domain(currd)) ) @@ -3011,6 +3048,7 @@ >> int hvm_hap_nested_page_fault(paddr_t gpa, unsigned long gla, >> /* Spurious fault? PoD and log-dirty also take this path. */ >> if ( p2m_is_ram(p2mt) ) >> { >> + rc = 1; >> /* >> * Page log dirty is always done with order 0. If this mfn resides >> in >> * a large page, we do not change other pages type within >> that large @@ -3019,9 +3057,15 @@ int >hvm_hap_nested_page_fault(paddr_t gpa, unsigned long gla, >> if ( npfec.write_access ) >> { >> paging_mark_dirty(currd, mfn_x(mfn)); >> + /* If p2m is really an altp2m, unlock here to avoid lock >> ordering >> + * violation when the change below is propagated from host p2m >> */ >> + if ( ap2m_active ) >> + __put_gfn(p2m, gfn); >> p2m_change_type_one(currd, gfn, p2m_ram_logdirty, >> p2m_ram_rw); >> + __put_gfn(ap2m_active ? hostp2m : p2m, gfn); >> + >> + goto out; >> } >> - rc = 1; >> goto out_put_gfn; >> } >> >> @@ -3031,7 +3075,9 @@ int hvm_hap_nested_page_fault(paddr_t gpa, >unsigned long gla, >> rc = fall_through; >> >> out_put_gfn: >> - put_gfn(currd, gfn); >> + __put_gfn(p2m, gfn); >> + if ( ap2m_active ) >> + __put_gfn(hostp2m, gfn); >> out: >> /* All of these are delayed until we exit, since we might >> * sleep on event ring wait queues, and we must not hold diff >> --git a/xen/arch/x86/mm/hap/Makefile b/xen/arch/x86/mm/hap/Makefile >> index 68f2bb5..216cd90 100644 >> --- a/xen/arch/x86/mm/hap/Makefile >> +++ b/xen/arch/x86/mm/hap/Makefile >> @@ -4,6 +4,7 @@ obj-y += guest_walk_3level.o >> obj-$(x86_64) += guest_walk_4level.o >> obj-y += nested_hap.o >> obj-y += nested_ept.o >> +obj-y += altp2m_hap.o >> >> guest_walk_%level.o: guest_walk.c Makefile >> $(CC) $(CFLAGS) -DGUEST_PAGING_LEVELS=$* -c $< -o $@ diff --git >> a/xen/arch/x86/mm/hap/altp2m_hap.c >b/xen/arch/x86/mm/hap/altp2m_hap.c >> new file mode 100644 >> index 0000000..52c7877 >> --- /dev/null >> +++ b/xen/arch/x86/mm/hap/altp2m_hap.c >> @@ -0,0 +1,98 @@ >> >+/********************************************************* >*********** >> +********** >> + * arch/x86/mm/hap/altp2m_hap.c >> + * >> + * Copyright (c) 2014 Intel Corporation. >> + * >> + * This program is free software; you can redistribute it and/or >> +modify >> + * it under the terms of the GNU General Public License as published >> +by >> + * the Free Software Foundation; either version 2 of the License, or >> + * (at your option) any later version. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. >> + * >> + * You should have received a copy of the GNU General Public License >> + * along with this program; if not, write to the Free Software >> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA >> +02111-1307 USA */ >> + >> +#include <asm/domain.h> >> +#include <asm/page.h> >> +#include <asm/paging.h> >> +#include <asm/p2m.h> >> +#include <asm/hap.h> >> +#include <asm/hvm/altp2m.h> >> + >> +#include "private.h" >> + >> +/* >> + * If the fault is for a not present entry: >> + * if the entry in the host p2m has a valid mfn, copy it and retry >> + * else indicate that outer handler should handle fault >> + * >> + * If the fault is for a present entry: >> + * indicate that outer handler should handle fault >> + */ >> + >> +int >> +altp2m_hap_nested_page_fault(struct vcpu *v, paddr_t gpa, >> + unsigned long gla, struct npfec npfec, >> + struct p2m_domain **ap2m) { >> + struct p2m_domain *hp2m = p2m_get_hostp2m(v->domain); >> + p2m_type_t p2mt; >> + p2m_access_t p2ma; >> + unsigned int page_order; >> + gfn_t gfn = _gfn(paddr_to_pfn(gpa)); >> + unsigned long mask; >> + mfn_t mfn; >> + int rv; >> + >> + *ap2m = p2m_get_altp2m(v); >> + >> + mfn = get_gfn_type_access(*ap2m, gfn_x(gfn), &p2mt, &p2ma, >> + 0, &page_order); >> + __put_gfn(*ap2m, gfn_x(gfn)); >> + >> + if ( mfn_x(mfn) != INVALID_MFN ) >> + return 0; >> + >> + mfn = get_gfn_type_access(hp2m, gfn_x(gfn), &p2mt, &p2ma, >> + P2M_ALLOC | P2M_UNSHARE, &page_order); >> + put_gfn(hp2m->domain, gfn_x(gfn)); > >To quote myself: > >--- >Please do at least give this function a name that reflects what it does (i.e., >try >to propagate changes from the host p2m to the altp2m), and change this >put_gfn() to match the __put_gfn() above. > >I'd prefer it if you moved this into mm/p2m.c as well. >--- > > -George
Got it - we have done this one for the next rev. Thanks Ravi _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
