[Xen-devel] [PATCH v3 1/3] x86/ioreq server(patch for 4.7): Rename p2m_mmio_write_dm to p2m_ioreq_server.

[Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>]

Previously p2m type p2m_mmio_write_dm was introduced for write-
protected memory pages whose write operations are supposed to be
forwarded to and emulated by an ioreq server. Yet limitations of
rangeset restrict the number of guest pages to be write-protected.

This patch replaces the p2m type p2m_mmio_write_dm with a new name:
p2m_ioreq_server, which means this p2m type can be claimed by one
ioreq server, instead of being tracked inside the rangeset of ioreq
server. Patches following up will add the related hvmop handling
code which map/unmap type p2m_ioreq_server to/from an ioreq server.

changes in v3:
  - According to Jan & George's comments, keep HVMMEM_mmio_write_dm
    for old xen interface versions, and replace it with HVMMEM_unused
    for xen interfaces newer than 4.7.0; For p2m_ioreq_server, a new
    enum - HVMMEM_ioreq_server is introduced for the get/set mem type
    interfaces;
  - Add George's Reviewed-by and Acked-by from Tim & Andrew.

changes in v2:
  - According to George Dunlap's comments, only rename the p2m type,
    with no behavior changes.

Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Signed-off-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>
Acked-by: Tim Deegan <tim@xxxxxxx>
Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: George Dunlap <george.dunlap@xxxxxxxxxx>
Cc: Keir Fraser <keir@xxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: Jun Nakajima <jun.nakajima@xxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
---
 xen/arch/x86/hvm/hvm.c          | 14 ++++++++------
 xen/arch/x86/mm/p2m-ept.c       |  2 +-
 xen/arch/x86/mm/p2m-pt.c        |  2 +-
 xen/arch/x86/mm/shadow/multi.c  |  2 +-
 xen/include/asm-x86/p2m.h       |  4 ++--
 xen/include/public/hvm/hvm_op.h |  8 +++++++-
 6 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index f24126d..874cb0f 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1857,7 +1857,7 @@ int hvm_hap_nested_page_fault(paddr_t gpa, unsigned long 
gla,
      */
     if ( (p2mt == p2m_mmio_dm) || 
          (npfec.write_access &&
-          (p2m_is_discard_write(p2mt) || (p2mt == p2m_mmio_write_dm))) )
+          (p2m_is_discard_write(p2mt) || (p2mt == p2m_ioreq_server))) )
     {
         __put_gfn(p2m, gfn);
         if ( ap2m_active )
@@ -5499,8 +5499,8 @@ long do_hvm_op(unsigned long op, 
XEN_GUEST_HANDLE_PARAM(void) arg)
             get_gfn_query_unlocked(d, a.pfn, &t);
             if ( p2m_is_mmio(t) )
                 a.mem_type =  HVMMEM_mmio_dm;
-            else if ( t == p2m_mmio_write_dm )
-                a.mem_type = HVMMEM_mmio_write_dm;
+            else if ( t == p2m_ioreq_server )
+                a.mem_type = HVMMEM_ioreq_server;
             else if ( p2m_is_readonly(t) )
                 a.mem_type =  HVMMEM_ram_ro;
             else if ( p2m_is_ram(t) )
@@ -5531,7 +5531,8 @@ long do_hvm_op(unsigned long op, 
XEN_GUEST_HANDLE_PARAM(void) arg)
             [HVMMEM_ram_rw]  = p2m_ram_rw,
             [HVMMEM_ram_ro]  = p2m_ram_ro,
             [HVMMEM_mmio_dm] = p2m_mmio_dm,
-            [HVMMEM_mmio_write_dm] = p2m_mmio_write_dm
+            [HVMMEM_unused] = p2m_invalid,
+            [HVMMEM_ioreq_server] = p2m_ioreq_server
         };
 
         if ( copy_from_guest(&a, arg, 1) )
@@ -5555,7 +5556,8 @@ long do_hvm_op(unsigned long op, 
XEN_GUEST_HANDLE_PARAM(void) arg)
              ((a.first_pfn + a.nr - 1) > domain_get_maximum_gpfn(d)) )
             goto setmemtype_fail;
             
-        if ( a.hvmmem_type >= ARRAY_SIZE(memtype) )
+        if ( a.hvmmem_type >= ARRAY_SIZE(memtype) ||
+             unlikely(a.hvmmem_type == HVMMEM_unused) )
             goto setmemtype_fail;
 
         while ( a.nr > start_iter )
@@ -5579,7 +5581,7 @@ long do_hvm_op(unsigned long op, 
XEN_GUEST_HANDLE_PARAM(void) arg)
             }
             if ( !p2m_is_ram(t) &&
                  (!p2m_is_hole(t) || a.hvmmem_type != HVMMEM_mmio_dm) &&
-                 (t != p2m_mmio_write_dm || a.hvmmem_type != HVMMEM_ram_rw) )
+                 (t != p2m_ioreq_server || a.hvmmem_type != HVMMEM_ram_rw) )
             {
                 put_gfn(d, pfn);
                 goto setmemtype_fail;
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 3cb6868..380ec25 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -171,7 +171,7 @@ static void ept_p2m_type_to_flags(struct p2m_domain *p2m, 
ept_entry_t *entry,
             entry->a = entry->d = !!cpu_has_vmx_ept_ad;
             break;
         case p2m_grant_map_ro:
-        case p2m_mmio_write_dm:
+        case p2m_ioreq_server:
             entry->r = 1;
             entry->w = entry->x = 0;
             entry->a = !!cpu_has_vmx_ept_ad;
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index 3d80612..eabd2e3 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -94,7 +94,7 @@ static unsigned long p2m_type_to_flags(p2m_type_t t, mfn_t 
mfn,
     default:
         return flags | _PAGE_NX_BIT;
     case p2m_grant_map_ro:
-    case p2m_mmio_write_dm:
+    case p2m_ioreq_server:
         return flags | P2M_BASE_FLAGS | _PAGE_NX_BIT;
     case p2m_ram_ro:
     case p2m_ram_logdirty:
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index e5c8499..c81302a 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -3225,7 +3225,7 @@ static int sh_page_fault(struct vcpu *v,
 
     /* Need to hand off device-model MMIO to the device model */
     if ( p2mt == p2m_mmio_dm
-         || (p2mt == p2m_mmio_write_dm && ft == ft_demand_write) )
+         || (p2mt == p2m_ioreq_server && ft == ft_demand_write) )
     {
         gpa = guest_walk_to_gpa(&gw);
         goto mmio;
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 5392eb0..ee2ea9c 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -71,7 +71,7 @@ typedef enum {
     p2m_ram_shared = 12,          /* Shared or sharable memory */
     p2m_ram_broken = 13,          /* Broken page, access cause domain crash */
     p2m_map_foreign  = 14,        /* ram pages from foreign domain */
-    p2m_mmio_write_dm = 15,       /* Read-only; writes go to the device model 
*/
+    p2m_ioreq_server = 15,
 } p2m_type_t;
 
 /* Modifiers to the query */
@@ -112,7 +112,7 @@ typedef unsigned int p2m_query_t;
                       | p2m_to_mask(p2m_ram_ro)         \
                       | p2m_to_mask(p2m_grant_map_ro)   \
                       | p2m_to_mask(p2m_ram_shared)     \
-                      | p2m_to_mask(p2m_mmio_write_dm))
+                      | p2m_to_mask(p2m_ioreq_server))
 
 /* Write-discard types, which should discard the write operations */
 #define P2M_DISCARD_WRITE_TYPES (p2m_to_mask(p2m_ram_ro)     \
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 1606185..b3e45cf 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -83,7 +83,13 @@ typedef enum {
     HVMMEM_ram_rw,             /* Normal read/write guest RAM */
     HVMMEM_ram_ro,             /* Read-only; writes are discarded */
     HVMMEM_mmio_dm,            /* Reads and write go to the device model */
-    HVMMEM_mmio_write_dm       /* Read-only; writes go to the device model */
+#if __XEN_INTERFACE_VERSION__ < 0x00040700
+    HVMMEM_mmio_write_dm,      /* Read-only; writes go to the device model */
+#else
+    HVMMEM_unused,             /* Placeholder; setting memory to this type
+                                  will fail for code after 4.7.0 */
+#endif
+    HVMMEM_ioreq_server
 } hvmmem_type_t;
 
 /* Following tools-only interfaces may change in future. */
-- 
1.9.1


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