[PATCH v6 08/11] x86/mm: add vmtrace_buf resource type

["Michał Leszczyński" <michal.leszczynski@cert.pl>]

From: Michal Leszczynski <michal.leszczynski@cert.pl>

Allow to map processor trace buffer using
acquire_resource().

Signed-off-by: Michal Leszczynski <michal.leszczynski@cert.pl>
---
 xen/common/memory.c         | 31 +++++++++++++++++++++++++++++++
 xen/include/public/memory.h |  1 +
 2 files changed, 32 insertions(+)

diff --git a/xen/common/memory.c b/xen/common/memory.c
index eb42f883df..c0a22eb60f 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -1007,6 +1007,32 @@ static long xatp_permission_check(struct domain *d, unsigned int space)
     return xsm_add_to_physmap(XSM_TARGET, current->domain, d);
 }
 
+static int acquire_vmtrace_buf(struct domain *d, unsigned int id,
+                               uint64_t frame,
+                               uint64_t nr_frames,
+                               xen_pfn_t mfn_list[])
+{
+    mfn_t mfn;
+    unsigned int i;
+    uint64_t size;
+    struct vcpu *v = domain_vcpu(d, id);
+
+    if ( !v || !v->vmtrace.pt_buf )
+        return -EINVAL;
+
+    mfn = page_to_mfn(v->vmtrace.pt_buf);
+    size = v->domain->processor_trace_buf_kb * KB(1);
+
+    if ( (frame > (size >> PAGE_SHIFT)) ||
+         (nr_frames > ((size >> PAGE_SHIFT) - frame)) )
+        return -EINVAL;
+
+    for ( i = 0; i < nr_frames; i++ )
+        mfn_list[i] = mfn_x(mfn_add(mfn, frame + i));
+
+    return 0;
+}
+
 static int acquire_grant_table(struct domain *d, unsigned int id,
                                unsigned long frame,
                                unsigned int nr_frames,
@@ -1117,6 +1143,11 @@ static int acquire_resource(
                                  mfn_list);
         break;
 
+    case XENMEM_resource_vmtrace_buf:
+        rc = acquire_vmtrace_buf(d, xmar.id, xmar.frame, xmar.nr_frames,
+                                 mfn_list);
+        break;
+
     default:
         rc = arch_acquire_resource(d, xmar.type, xmar.id, xmar.frame,
                                    xmar.nr_frames, mfn_list);
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 21057ed78e..f4c905a10e 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -625,6 +625,7 @@ struct xen_mem_acquire_resource {
 
 #define XENMEM_resource_ioreq_server 0
 #define XENMEM_resource_grant_table 1
+#define XENMEM_resource_vmtrace_buf 2
 
     /*
      * IN - a type-specific resource identifier, which must be zero
-- 
2.17.1