Merge branch 'stable/bug-fixes-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

* 'stable/bug-fixes-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: Allow PV-OPS kernel to detect whether XSAVE is supported
  xen: just completely disable XSAVE
  xen/debug: Don't be so verbose with WARN on 1-1 mapping errors.
  xen: events: fix error checks in bind_*_to_irqhandler()

2 files changed, 9 insertions, 16 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 49dbd78ec3cb..e3c6a06cf725 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -238,6 +238,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 static __init void xen_init_cpuid_mask(void)
 {
         unsigned int ax, bx, cx, dx;
+        unsigned int xsave_mask;
 
         cpuid_leaf1_edx_mask =
                 ~((1 << X86_FEATURE_MCE)  |  /* disable MCE */
@@ -249,24 +250,16 @@ static __init void xen_init_cpuid_mask(void)
                 cpuid_leaf1_edx_mask &=
                         ~((1 << X86_FEATURE_APIC) |  /* disable local APIC */
                           (1 << X86_FEATURE_ACPI));  /* disable ACPI */
-
         ax = 1;
-        cx = 0;
         xen_cpuid(&ax, &bx, &cx, &dx);
 
-        /* cpuid claims we support xsave; try enabling it to see what happens */
-        if (cx & (1 << (X86_FEATURE_XSAVE % 32))) {
-                unsigned long cr4;
-
-                set_in_cr4(X86_CR4_OSXSAVE);
-                
-                cr4 = read_cr4();
+        xsave_mask =
+                (1 << (X86_FEATURE_XSAVE % 32)) |
+                (1 << (X86_FEATURE_OSXSAVE % 32));
 
-                if ((cr4 & X86_CR4_OSXSAVE) == 0)
-                        cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));
-
-                clear_in_cr4(X86_CR4_OSXSAVE);
-        }
+        /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
+        if ((cx & xsave_mask) != xsave_mask)
+                cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
 }
 
 static void xen_set_debugreg(int reg, unsigned long val)
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index c82df6c9c0f0..a991b57f91fe 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -565,13 +565,13 @@ pte_t xen_make_pte_debug(pteval_t pte)
         if (io_page &&
             (xen_initial_domain() || addr >= ISA_END_ADDRESS)) {
                 other_addr = pfn_to_mfn(addr >> PAGE_SHIFT) << PAGE_SHIFT;
-                WARN(addr != other_addr,
+                WARN_ONCE(addr != other_addr,
                         "0x%lx is using VM_IO, but it is 0x%lx!\n",
                         (unsigned long)addr, (unsigned long)other_addr);
         } else {
                 pteval_t iomap_set = (_pte.pte & PTE_FLAGS_MASK) & _PAGE_IOMAP;
                 other_addr = (_pte.pte & PTE_PFN_MASK);
-                WARN((addr == other_addr) && (!io_page) && (!iomap_set),
+                WARN_ONCE((addr == other_addr) && (!io_page) && (!iomap_set),
                         "0x%lx is missing VM_IO (and wasn't fixed)!\n",
                         (unsigned long)addr);
         }