[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] mem_access: Use monitor_traps instead of mem_access_send_req
On 07/28/2016 10:35 PM, Tamas K Lengyel wrote: > The two functions monitor_traps and mem_access_send_req duplicate > some of the same functionality. The mem_access_send_req however leaves a > lot of the standard vm_event fields to be filled by other functions. > > Since mem_access events go on the monitor ring in this patch we consolidate > all paths to use monitor_traps to place events on the ring and to fill in > the common parts of the requests. > > Signed-off-by: Tamas K Lengyel <tamas.lengyel@xxxxxxxxxxxx> > --- > Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> > Cc: Julien Grall <julien.grall@xxxxxxx> > Cc: Jan Beulich <jbeulich@xxxxxxxx> > Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> > Cc: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx> > Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx> > --- > xen/arch/arm/p2m.c | 69 > +++++++++++++++++++-------------------- > xen/arch/x86/hvm/hvm.c | 16 ++++++--- > xen/arch/x86/hvm/monitor.c | 6 ++++ > xen/arch/x86/mm/p2m.c | 24 ++------------ > xen/common/mem_access.c | 11 ------- > xen/include/asm-x86/hvm/monitor.h | 2 ++ > xen/include/asm-x86/p2m.h | 13 +++++--- > xen/include/xen/mem_access.h | 7 ---- > 8 files changed, 63 insertions(+), 85 deletions(-) > > diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c > index d82349c..df898a3 100644 > --- a/xen/arch/arm/p2m.c > +++ b/xen/arch/arm/p2m.c > @@ -5,7 +5,7 @@ > #include <xen/domain_page.h> > #include <xen/bitops.h> > #include <xen/vm_event.h> > -#include <xen/mem_access.h> > +#include <xen/monitor.h> > #include <xen/iocap.h> > #include <public/vm_event.h> > #include <asm/flushtlb.h> > @@ -1642,12 +1642,41 @@ void __init setup_virt_paging(void) > smp_call_function(setup_virt_paging_one, (void *)val, 1); > } > > +static int > +__p2m_mem_access_send_req(paddr_t gpa, vaddr_t gla, const struct npfec npfec, > + xenmem_access_t xma) > +{ > + struct vcpu *v = current; > + vm_event_request_t req = {}; > + bool_t sync = (xma == XENMEM_access_n2rwx) ? 0 : 1; > + > + req.reason = VM_EVENT_REASON_MEM_ACCESS; > + > + /* Send request to mem access subscriber */ > + req.u.mem_access.gfn = gpa >> PAGE_SHIFT; > + req.u.mem_access.offset = gpa & ((1 << PAGE_SHIFT) - 1); > + if ( npfec.gla_valid ) > + { > + req.u.mem_access.flags |= MEM_ACCESS_GLA_VALID; > + req.u.mem_access.gla = gla; > + > + if ( npfec.kind == npfec_kind_with_gla ) > + req.u.mem_access.flags |= MEM_ACCESS_FAULT_WITH_GLA; > + else if ( npfec.kind == npfec_kind_in_gpt ) > + req.u.mem_access.flags |= MEM_ACCESS_FAULT_IN_GPT; > + } > + req.u.mem_access.flags |= npfec.read_access ? MEM_ACCESS_R : 0; > + req.u.mem_access.flags |= npfec.write_access ? MEM_ACCESS_W : 0; > + req.u.mem_access.flags |= npfec.insn_fetch ? MEM_ACCESS_X : 0; > + > + return monitor_traps(v, sync, &req); > +} > + > bool_t p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec > npfec) > { > int rc; > bool_t violation; > xenmem_access_t xma; > - vm_event_request_t *req; > struct vcpu *v = current; > struct p2m_domain *p2m = p2m_get_hostp2m(v->domain); > > @@ -1734,40 +1763,8 @@ bool_t p2m_mem_access_check(paddr_t gpa, vaddr_t gla, > const struct npfec npfec) > return false; > } > > - req = xzalloc(vm_event_request_t); > - if ( req ) > - { > - req->reason = VM_EVENT_REASON_MEM_ACCESS; > - > - /* Pause the current VCPU */ > - if ( xma != XENMEM_access_n2rwx ) > - req->flags |= VM_EVENT_FLAG_VCPU_PAUSED; > - > - /* Send request to mem access subscriber */ > - req->u.mem_access.gfn = gpa >> PAGE_SHIFT; > - req->u.mem_access.offset = gpa & ((1 << PAGE_SHIFT) - 1); > - if ( npfec.gla_valid ) > - { > - req->u.mem_access.flags |= MEM_ACCESS_GLA_VALID; > - req->u.mem_access.gla = gla; > - > - if ( npfec.kind == npfec_kind_with_gla ) > - req->u.mem_access.flags |= MEM_ACCESS_FAULT_WITH_GLA; > - else if ( npfec.kind == npfec_kind_in_gpt ) > - req->u.mem_access.flags |= MEM_ACCESS_FAULT_IN_GPT; > - } > - req->u.mem_access.flags |= npfec.read_access ? MEM_ACCESS_R : 0; > - req->u.mem_access.flags |= npfec.write_access ? MEM_ACCESS_W : 0; > - req->u.mem_access.flags |= npfec.insn_fetch ? MEM_ACCESS_X : 0; > - req->vcpu_id = v->vcpu_id; The line setting req->vcpu_id has been removed here ... > - > - mem_access_send_req(v->domain, req); > - xfree(req); > - } > - > - /* Pause the current VCPU */ > - if ( xma != XENMEM_access_n2rwx ) > - vm_event_vcpu_pause(v); > + if ( __p2m_mem_access_send_req(gpa, gla, npfec, xma) < 0 ) > + domain_crash(v->domain); > > return false; > } > diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c > index daaee1d..688370d 100644 > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -1707,7 +1707,7 @@ int hvm_hap_nested_page_fault(paddr_t gpa, unsigned > long gla, > int rc, fall_through = 0, paged = 0; > int sharing_enomem = 0; > vm_event_request_t *req_ptr = NULL; > - bool_t ap2m_active; > + bool_t ap2m_active, sync = 0; > > /* On Nested Virtualization, walk the guest page table. > * If this succeeds, all is fine. > @@ -1846,11 +1846,12 @@ int hvm_hap_nested_page_fault(paddr_t gpa, unsigned > long gla, > } > } > > - if ( p2m_mem_access_check(gpa, gla, npfec, &req_ptr) ) > - { > + sync = p2m_mem_access_check(gpa, gla, npfec, &req_ptr); > + > + if ( !sync ) { > fall_through = 1; > } else { > - /* Rights not promoted, vcpu paused, work here is done */ > + /* Rights not promoted (aka. sync event), work here is done > */ > rc = 1; > goto out_put_gfn; > } > @@ -1956,7 +1957,12 @@ out: > } > if ( req_ptr ) > { > - mem_access_send_req(currd, req_ptr); > + if ( hvm_monitor_mem_access(curr, sync, req_ptr) < 0 ) > + { > + /* Crash the domain */ > + rc = 0; > + } > + > xfree(req_ptr); > } > return rc; > diff --git a/xen/arch/x86/hvm/monitor.c b/xen/arch/x86/hvm/monitor.c > index 7277c12..c7285c6 100644 > --- a/xen/arch/x86/hvm/monitor.c > +++ b/xen/arch/x86/hvm/monitor.c > @@ -152,6 +152,12 @@ int hvm_monitor_cpuid(unsigned long insn_length) > return monitor_traps(curr, 1, &req); > } > > +int hvm_monitor_mem_access(struct vcpu* v, bool_t sync, > + vm_event_request_t *req) > +{ > + return monitor_traps(v, sync, req); > +} > + > /* > * Local variables: > * mode: C > diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c > index 812dbf6..27f9d26 100644 > --- a/xen/arch/x86/mm/p2m.c > +++ b/xen/arch/x86/mm/p2m.c > @@ -1728,13 +1728,8 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long > gla, > if ( req ) > { > *req_ptr = req; > - req->reason = VM_EVENT_REASON_MEM_ACCESS; > - > - /* Pause the current VCPU */ > - if ( p2ma != p2m_access_n2rwx ) > - req->flags |= VM_EVENT_FLAG_VCPU_PAUSED; > > - /* Send request to mem event */ > + req->reason = VM_EVENT_REASON_MEM_ACCESS; > req->u.mem_access.gfn = gfn; > req->u.mem_access.offset = gpa & ((1 << PAGE_SHIFT) - 1); > if ( npfec.gla_valid ) > @@ -1750,23 +1745,10 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned > long gla, > req->u.mem_access.flags |= npfec.read_access ? MEM_ACCESS_R : 0; > req->u.mem_access.flags |= npfec.write_access ? MEM_ACCESS_W : 0; > req->u.mem_access.flags |= npfec.insn_fetch ? MEM_ACCESS_X : 0; > - req->vcpu_id = v->vcpu_id; ... and here, and as such it doesn't seem to get set anywhere else now. Am I missing an code path outside of this patch where req->vcpu_id is being correctly set so this has become unnecessary? Thanks, Razvan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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