[PATCH v2 for-next v2 7/8] x86/mm: move check_descriptor to pv/mm.c

[Wei Liu <wei.liu2@citrix.com>]

It's only needed there. Also make it static and delete the declaration
from mm.h.

No functional change.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/arch/x86/pv/mm.c     | 86 +++++++++++++++++++++++++++++++++++++++++++++++
 xen/arch/x86/x86_64/mm.c | 87 ------------------------------------------------
 xen/include/asm-x86/mm.h |  2 --
 3 files changed, 86 insertions(+), 89 deletions(-)

diff --git a/xen/arch/x86/pv/mm.c b/xen/arch/x86/pv/mm.c
index 48d3fe184b..96f2431756 100644
--- a/xen/arch/x86/pv/mm.c
+++ b/xen/arch/x86/pv/mm.c
@@ -220,6 +220,92 @@ static void invalidate_shadow_ldt(struct vcpu *v, int flush)
     spin_unlock(&v->arch.pv_vcpu.shadow_ldt_lock);
 }
 
+/* Returns TRUE if given descriptor is valid for GDT or LDT. */
+static int check_descriptor(const struct domain *dom, struct desc_struct *d)
+{
+    u32 a = d->a, b = d->b;
+    u16 cs;
+    unsigned int dpl;
+
+    /* A not-present descriptor will always fault, so is safe. */
+    if ( !(b & _SEGMENT_P) )
+        return 1;
+
+    /* Check and fix up the DPL. */
+    dpl = (b >> 13) & 3;
+    __fixup_guest_selector(dom, dpl);
+    b = (b & ~_SEGMENT_DPL) | (dpl << 13);
+
+    /* All code and data segments are okay. No base/limit checking. */
+    if ( (b & _SEGMENT_S) )
+    {
+        if ( is_pv_32bit_domain(dom) )
+        {
+            unsigned long base, limit;
+
+            if ( b & _SEGMENT_L )
+                goto bad;
+
+            /*
+             * Older PAE Linux guests use segments which are limited to
+             * 0xf6800000. Extend these to allow access to the larger read-only
+             * M2P table available in 32on64 mode.
+             */
+            base = (b & (0xff << 24)) | ((b & 0xff) << 16) | (a >> 16);
+
+            limit = (b & 0xf0000) | (a & 0xffff);
+            limit++; /* We add one because limit is inclusive. */
+
+            if ( (b & _SEGMENT_G) )
+                limit <<= 12;
+
+            if ( (base == 0) && (limit > HYPERVISOR_COMPAT_VIRT_START(dom)) )
+            {
+                a |= 0x0000ffff;
+                b |= 0x000f0000;
+            }
+        }
+
+        goto good;
+    }
+
+    /* Invalid type 0 is harmless. It is used for 2nd half of a call gate. */
+    if ( (b & _SEGMENT_TYPE) == 0x000 )
+        return 1;
+
+    /* Everything but a call gate is discarded here. */
+    if ( (b & _SEGMENT_TYPE) != 0xc00 )
+        goto bad;
+
+    /* Validate the target code selector. */
+    cs = a >> 16;
+    if ( !guest_gate_selector_okay(dom, cs) )
+        goto bad;
+    /*
+     * Force DPL to zero, causing a GP fault with its error code indicating
+     * the gate in use, allowing emulation. This is necessary because with
+     * native guests (kernel in ring 3) call gates cannot be used directly
+     * to transition from user to kernel mode (and whether a gate is used
+     * to enter the kernel can only be determined when the gate is being
+     * used), and with compat guests call gates cannot be used at all as
+     * there are only 64-bit ones.
+     * Store the original DPL in the selector's RPL field.
+     */
+    b &= ~_SEGMENT_DPL;
+    cs = (cs & ~3) | dpl;
+    a = (a & 0xffffU) | (cs << 16);
+
+    /* Reserved bits must be zero. */
+    if ( b & (is_pv_32bit_domain(dom) ? 0xe0 : 0xff) )
+        goto bad;
+
+ good:
+    d->a = a;
+    d->b = b;
+    return 1;
+ bad:
+    return 0;
+}
 
 static int alloc_segdesc_page(struct page_info *page)
 {
diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c
index 19a14e8829..0bf85a59ed 100644
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -1018,93 +1018,6 @@ long subarch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     return rc;
 }
 
-/* Returns TRUE if given descriptor is valid for GDT or LDT. */
-int check_descriptor(const struct domain *dom, struct desc_struct *d)
-{
-    u32 a = d->a, b = d->b;
-    u16 cs;
-    unsigned int dpl;
-
-    /* A not-present descriptor will always fault, so is safe. */
-    if ( !(b & _SEGMENT_P) ) 
-        return 1;
-
-    /* Check and fix up the DPL. */
-    dpl = (b >> 13) & 3;
-    __fixup_guest_selector(dom, dpl);
-    b = (b & ~_SEGMENT_DPL) | (dpl << 13);
-
-    /* All code and data segments are okay. No base/limit checking. */
-    if ( (b & _SEGMENT_S) )
-    {
-        if ( is_pv_32bit_domain(dom) )
-        {
-            unsigned long base, limit;
-
-            if ( b & _SEGMENT_L )
-                goto bad;
-
-            /*
-             * Older PAE Linux guests use segments which are limited to
-             * 0xf6800000. Extend these to allow access to the larger read-only
-             * M2P table available in 32on64 mode.
-             */
-            base = (b & (0xff << 24)) | ((b & 0xff) << 16) | (a >> 16);
-
-            limit = (b & 0xf0000) | (a & 0xffff);
-            limit++; /* We add one because limit is inclusive. */
-
-            if ( (b & _SEGMENT_G) )
-                limit <<= 12;
-
-            if ( (base == 0) && (limit > HYPERVISOR_COMPAT_VIRT_START(dom)) )
-            {
-                a |= 0x0000ffff;
-                b |= 0x000f0000;
-            }
-        }
-
-        goto good;
-    }
-
-    /* Invalid type 0 is harmless. It is used for 2nd half of a call gate. */
-    if ( (b & _SEGMENT_TYPE) == 0x000 )
-        return 1;
-
-    /* Everything but a call gate is discarded here. */
-    if ( (b & _SEGMENT_TYPE) != 0xc00 )
-        goto bad;
-
-    /* Validate the target code selector. */
-    cs = a >> 16;
-    if ( !guest_gate_selector_okay(dom, cs) )
-        goto bad;
-    /*
-     * Force DPL to zero, causing a GP fault with its error code indicating
-     * the gate in use, allowing emulation. This is necessary because with
-     * native guests (kernel in ring 3) call gates cannot be used directly
-     * to transition from user to kernel mode (and whether a gate is used
-     * to enter the kernel can only be determined when the gate is being
-     * used), and with compat guests call gates cannot be used at all as
-     * there are only 64-bit ones.
-     * Store the original DPL in the selector's RPL field.
-     */
-    b &= ~_SEGMENT_DPL;
-    cs = (cs & ~3) | dpl;
-    a = (a & 0xffffU) | (cs << 16);
-
-    /* Reserved bits must be zero. */
-    if ( b & (is_pv_32bit_domain(dom) ? 0xe0 : 0xff) )
-        goto bad;
-        
- good:
-    d->a = a;
-    d->b = b;
-    return 1;
- bad:
-    return 0;
-}
-
 int pagefault_by_memadd(unsigned long addr, struct cpu_user_regs *regs)
 {
     struct domain *d = current->domain;
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 8e2bf91070..ca70f14500 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -411,8 +411,6 @@ static inline int get_page_and_type(struct page_info *page,
     ASSERT(((_p)->count_info & PGC_count_mask) != 0);          \
     ASSERT(page_get_owner(_p) == (_d))
 
-int check_descriptor(const struct domain *, struct desc_struct *d);
-
 extern bool_t opt_allow_superpage;
 extern paddr_t mem_hotplug;
 
-- 
2.11.0


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