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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-12 10:09:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-12 10:09:14 -0700
commit5836e422e5ca6d36d552f700916436e01cbd2066 (patch)
treed58dd8ff5a572b6f9569102f4c7076bd3e90e98a
parentdc2a24816637ff6c60f08c4245aba01c6e9b6a79 (diff)
parent69861e0a52f8733355ce246f0db15e1b240ad667 (diff)
Merge tag 'for-linus-4.12b-rc0c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross: "This contains two fixes for booting under Xen introduced during this merge window and two fixes for older problems, where one is just much more probable due to another merge window change" * tag 'for-linus-4.12b-rc0c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: adjust early dom0 p2m handling to xen hypervisor behavior x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen xen/x86: Do not call xen_init_time_ops() until shared_info is initialized x86/xen: fix xsave capability setting
-rw-r--r--arch/x86/kernel/cpu/amd.c5
-rw-r--r--arch/x86/xen/enlighten_pv.c42
-rw-r--r--arch/x86/xen/mmu_pv.c7
-rw-r--r--arch/x86/xen/time.c2
4 files changed, 24 insertions, 32 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index ee8f11800295..bb5abe8f5fd4 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -799,8 +799,9 @@ static void init_amd(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
- /* AMD CPUs don't reset SS attributes on SYSRET */
- set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+ /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
+ if (!cpu_has(c, X86_FEATURE_XENPV))
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
}
#ifdef CONFIG_X86_32
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index a732bc2b9dfc..7cd442690f9d 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -277,31 +277,19 @@ static bool __init xen_check_mwait(void)
static bool __init xen_check_xsave(void)
{
- unsigned int err, eax, edx;
+ unsigned int cx, xsave_mask;
- /*
- * Xen 4.0 and older accidentally leaked the host XSAVE flag into guest
- * view, despite not being able to support guests using the
- * functionality. Probe for the actual availability of XSAVE by seeing
- * whether xgetbv executes successfully or raises #UD.
- */
- asm volatile("1: .byte 0x0f,0x01,0xd0\n\t" /* xgetbv */
- "xor %[err], %[err]\n"
- "2:\n\t"
- ".pushsection .fixup,\"ax\"\n\t"
- "3: movl $1,%[err]\n\t"
- "jmp 2b\n\t"
- ".popsection\n\t"
- _ASM_EXTABLE(1b, 3b)
- : [err] "=r" (err), "=a" (eax), "=d" (edx)
- : "c" (0));
-
- return err == 0;
+ cx = cpuid_ecx(1);
+
+ xsave_mask = (1 << (X86_FEATURE_XSAVE % 32)) |
+ (1 << (X86_FEATURE_OSXSAVE % 32));
+
+ /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
+ return (cx & xsave_mask) == xsave_mask;
}
static void __init xen_init_capabilities(void)
{
- setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
setup_force_cpu_cap(X86_FEATURE_XENPV);
setup_clear_cpu_cap(X86_FEATURE_DCA);
setup_clear_cpu_cap(X86_FEATURE_APERFMPERF);
@@ -317,10 +305,7 @@ static void __init xen_init_capabilities(void)
else
setup_clear_cpu_cap(X86_FEATURE_MWAIT);
- if (xen_check_xsave()) {
- setup_force_cpu_cap(X86_FEATURE_XSAVE);
- setup_force_cpu_cap(X86_FEATURE_OSXSAVE);
- } else {
+ if (!xen_check_xsave()) {
setup_clear_cpu_cap(X86_FEATURE_XSAVE);
setup_clear_cpu_cap(X86_FEATURE_OSXSAVE);
}
@@ -988,6 +973,13 @@ void xen_setup_shared_info(void)
#endif
xen_setup_mfn_list_list();
+
+ /*
+ * Now that shared info is set up we can start using routines that
+ * point to pvclock area.
+ */
+ if (system_state == SYSTEM_BOOTING)
+ xen_init_time_ops();
}
/* This is called once we have the cpu_possible_mask */
@@ -1286,8 +1278,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
x86_init.oem.arch_setup = xen_arch_setup;
x86_init.oem.banner = xen_banner;
- xen_init_time_ops();
-
/*
* Set up some pagetable state before starting to set any ptes.
*/
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 9d9ae6650aa1..7397d8b8459d 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2025,7 +2025,8 @@ static unsigned long __init xen_read_phys_ulong(phys_addr_t addr)
/*
* Translate a virtual address to a physical one without relying on mapped
- * page tables.
+ * page tables. Don't rely on big pages being aligned in (guest) physical
+ * space!
*/
static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
{
@@ -2046,7 +2047,7 @@ static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
sizeof(pud)));
if (!pud_present(pud))
return 0;
- pa = pud_pfn(pud) << PAGE_SHIFT;
+ pa = pud_val(pud) & PTE_PFN_MASK;
if (pud_large(pud))
return pa + (vaddr & ~PUD_MASK);
@@ -2054,7 +2055,7 @@ static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
sizeof(pmd)));
if (!pmd_present(pmd))
return 0;
- pa = pmd_pfn(pmd) << PAGE_SHIFT;
+ pa = pmd_val(pmd) & PTE_PFN_MASK;
if (pmd_large(pmd))
return pa + (vaddr & ~PMD_MASK);
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 090c7eb4dca9..a1895a8e85c1 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -406,7 +406,7 @@ static void __init xen_time_init(void)
pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
}
-void __init xen_init_time_ops(void)
+void __ref xen_init_time_ops(void)
{
pv_time_ops = xen_time_ops;