[Xen-changelog] [xen-unstable] x86: further adjustments to arch_set_info_guest() after c/s 23142:f5e8d152a565

[Xen patchbot-unstable <patchbot@xxxxxxx>]

# HG changeset patch
# User Jan Beulich <jbeulich@xxxxxxxxxx>
# Date 1305636945 -3600
# Node ID 3e8e1800d4720f6e91d042ff97aa67a4465c9b40
# Parent  e5757cc64c8f3d924acb2310b695605b7c18e6e1
x86: further adjustments to arch_set_info_guest() after c/s 23142:f5e8d152a565

The adjustments to v->arch.user_regs.eflags and the initialization of
the int80 direct trap must be done earlier (namely before the function
may bail because of inconsistencies between input and stored state on
an already initialised vCPU) so that stored state is consistent, and
for arch_get_info_guest() to not have its eflags related BUG_ON()
triggered.

Further, v->arch.pv_vcpu.ctrlreg[] indices 3 and 1 aren't being kept
up to date while the domain is running, so consistency checks must
instead be done against v->arch.guest_table{,_user}.

Additionally, for 64-bit pv domains, CR1 must also be checked to be
consistent with the kernel mode setting for the vCPU, and the whole
CR1 checking should not be done for 32-bit pv domains.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---


diff -r e5757cc64c8f -r 3e8e1800d472 xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c     Mon May 16 13:34:25 2011 +0100
+++ b/xen/arch/x86/domain.c     Tue May 17 13:55:45 2011 +0100
@@ -843,6 +843,15 @@
         goto out;
     }
 
+    init_int80_direct_trap(v);
+
+    /* IOPL privileges are virtualised. */
+    v->arch.pv_vcpu.iopl = (v->arch.user_regs.eflags >> 12) & 3;
+    v->arch.user_regs.eflags &= ~X86_EFLAGS_IOPL;
+
+    /* Ensure real hardware interrupts are enabled. */
+    v->arch.user_regs.eflags |= X86_EFLAGS_IF;
+
     if ( !v->is_initialised )
     {
         v->arch.pv_vcpu.ldt_base = c(ldt_base);
@@ -850,11 +859,27 @@
     }
     else
     {
-        bool_t fail = v->arch.pv_vcpu.ctrlreg[3] != c(ctrlreg[3]);
+        unsigned long pfn = pagetable_get_pfn(v->arch.guest_table);
+        bool_t fail;
 
+        if ( !compat )
+        {
+            fail = xen_pfn_to_cr3(pfn) != c.nat->ctrlreg[3];
 #ifdef CONFIG_X86_64
-        fail |= v->arch.pv_vcpu.ctrlreg[1] != c(ctrlreg[1]);
+            if ( pagetable_is_null(v->arch.guest_table_user) )
+                fail |= c.nat->ctrlreg[1] || !(flags & VGCF_in_kernel);
+            else
+            {
+                pfn = pagetable_get_pfn(v->arch.guest_table_user);
+                fail |= xen_pfn_to_cr3(pfn) != c.nat->ctrlreg[1];
+            }
+        } else {
+            l4_pgentry_t *l4tab = __va(pfn_to_paddr(pfn));
+
+            pfn = l4e_get_pfn(*l4tab);
+            fail = compat_pfn_to_cr3(pfn) != c.cmp->ctrlreg[3];
 #endif
+        }
 
         for ( i = 0; i < ARRAY_SIZE(v->arch.pv_vcpu.gdt_frames); ++i )
             fail |= v->arch.pv_vcpu.gdt_frames[i] != c(gdt_frames[i]);
@@ -894,15 +919,6 @@
     v->arch.pv_vcpu.ctrlreg[0] &= X86_CR0_TS;
     v->arch.pv_vcpu.ctrlreg[0] |= read_cr0() & ~X86_CR0_TS;
 
-    init_int80_direct_trap(v);
-
-    /* IOPL privileges are virtualised. */
-    v->arch.pv_vcpu.iopl = (v->arch.user_regs.eflags >> 12) & 3;
-    v->arch.user_regs.eflags &= ~X86_EFLAGS_IOPL;
-
-    /* Ensure real hardware interrupts are enabled. */
-    v->arch.user_regs.eflags |= X86_EFLAGS_IF;
-
     cr4 = v->arch.pv_vcpu.ctrlreg[4];
     v->arch.pv_vcpu.ctrlreg[4] = cr4 ? pv_guest_cr4_fixup(v, cr4) :
         real_cr4_to_pv_guest_cr4(mmu_cr4_features);

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