[Xen-changelog] [xen master] x86/boot: Cache cpu_has_hypervisor very early on boot

[patchbot@xxxxxxx]

commit a7b88f0545ffe7d3ca8036beed1af92ac2be112a
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Nov 1 20:07:31 2019 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu Nov 21 15:49:54 2019 +0000

    x86/boot: Cache cpu_has_hypervisor very early on boot
    
    We cache Long Mode and No Execute early on boot, so take the opportunity to
    cache HYPERVISOR early as well.
    
    Replace opencoded early access to the feature bit.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
    Release-acked-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/x86/apic.c         | 2 +-
 xen/arch/x86/boot/head.S    | 4 ++++
 xen/arch/x86/efi/efi-boot.h | 6 ++++--
 xen/arch/x86/guest/xen.c    | 6 +-----
 xen/arch/x86/mm.c           | 3 +--
 5 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c
index a5f7b05d5a..a8ee18636f 100644
--- a/xen/arch/x86/apic.c
+++ b/xen/arch/x86/apic.c
@@ -1156,7 +1156,7 @@ static void __init check_deadline_errata(void)
     const struct x86_cpu_id *m;
     unsigned int rev;
 
-    if ( boot_cpu_has(X86_FEATURE_HYPERVISOR) )
+    if ( cpu_has_hypervisor )
         return;
 
     m = x86_match_cpu(deadline_match);
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index 77309e3c82..8d0ffbd1b0 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -630,6 +630,10 @@ trampoline_setup:
 
 1:
         /* Interrogate CPU extended features via CPUID. */
+        mov     $1, %eax
+        cpuid
+        mov     %ecx, sym_fs(boot_cpu_data) + 
CPUINFO_FEATURE_OFFSET(X86_FEATURE_HYPERVISOR)
+
         mov     $0x80000000,%eax
         cpuid
         shld    $16,%eax,%ecx
diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index cde193a771..232972eedf 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -637,11 +637,13 @@ static void __init efi_arch_handle_module(struct file 
*file, const CHAR16 *name,
 static void __init efi_arch_cpu(void)
 {
     uint32_t eax = cpuid_eax(0x80000000);
+    uint32_t *caps = boot_cpu_data.x86_capability;
+
+    caps[cpufeat_word(X86_FEATURE_HYPERVISOR)] = cpuid_ecx(1);
 
     if ( (eax >> 16) == 0x8000 && eax > 0x80000000 )
     {
-        boot_cpu_data.x86_capability[cpufeat_word(X86_FEATURE_SYSCALL)]
-            = cpuid_edx(0x80000001);
+        caps[cpufeat_word(X86_FEATURE_SYSCALL)] = cpuid_edx(0x80000001);
 
         if ( cpu_has_nx )
             trampoline_efer |= EFER_NX;
diff --git a/xen/arch/x86/guest/xen.c b/xen/arch/x86/guest/xen.c
index 7b7a5badab..a329e7c886 100644
--- a/xen/arch/x86/guest/xen.c
+++ b/xen/arch/x86/guest/xen.c
@@ -69,11 +69,7 @@ static void __init find_xen_leaves(void)
 
 void __init probe_hypervisor(void)
 {
-    if ( xen_guest )
-        return;
-
-    /* Too early to use cpu_has_hypervisor */
-    if ( !(cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_HYPERVISOR)) )
+    if ( xen_guest || !cpu_has_hypervisor )
         return;
 
     find_xen_leaves();
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 57f22775ac..bd8182f40f 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -6112,8 +6112,7 @@ const struct platform_bad_page *__init 
get_platform_badpages(unsigned int *array
     case 0x000506e0: /* errata SKL167 / SKW159 */
     case 0x000806e0: /* erratum KBL??? */
     case 0x000906e0: /* errata KBL??? / KBW114 / CFW103 */
-        *array_size = (cpuid_eax(0) >= 7 &&
-                       !(cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_HYPERVISOR)) 
&&
+        *array_size = (cpuid_eax(0) >= 7 && !cpu_has_hypervisor &&
                        (cpuid_count_ebx(7, 0) & 
cpufeat_mask(X86_FEATURE_HLE)));
         return &hle_bad_page;
     }
--
generated by git-patchbot for /home/xen/git/xen.git#master

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