[v2,4/4] x86/boot: Drop INVALID_VCPU

Commit Message

Andrew Cooper Jan. 9, 2020, 7:32 p.m. UTC

Now that NULL will fault at boot, there is no need for a special constant to
signify "current not set up yet".

Since c/s fae249d23413 "x86/boot: Rationalise stack handling during early
boot", the BSP cpu_info block is now consistently zero, so drop the adjacent
re-zeroing.

Signed-off-by: Andrew Cooper <[e-mail]>
---
CC: Jan Beulich <[e-mail]>
CC: Wei Liu <[e-mail]>
CC: Roger Pau Monné <[e-mail]>

v2:
 * Drop re-zeroign of the cpu_info block
---
 xen/arch/x86/cpu/mcheck/mce.c | 2 +-
 xen/arch/x86/domain_page.c    | 2 +-
 xen/arch/x86/setup.c          | 3 ---
 xen/arch/x86/tboot.c          | 2 +-
 xen/include/asm-x86/setup.h   | 3 ---
 5 files changed, 3 insertions(+), 9 deletions(-)

Comments

Jan Beulich Jan. 10, 2020, 4:52 p.m. UTC | #1

On 09.01.2020 20:32, Andrew Cooper wrote:
> Now that NULL will fault at boot, there is no need for a special constant to
> signify "current not set up yet".
> 
> Since c/s fae249d23413 "x86/boot: Rationalise stack handling during early
> boot", the BSP cpu_info block is now consistently zero, so drop the adjacent
> re-zeroing.
> 
> Signed-off-by: Andrew Cooper <[e-mail]>

Reviewed-by: Jan Beulich <[e-mail]>

Patch

diff --git a/xen/arch/x86/cpu/mcheck/mce.c b/xen/arch/x86/cpu/mcheck/mce.c
index 29f3f9c5e3..198595ff97 100644
--- a/xen/arch/x86/cpu/mcheck/mce.c
+++ b/xen/arch/x86/cpu/mcheck/mce.c
@@ -260,7 +260,7 @@  static int mca_init_global(uint32_t flags, struct mcinfo_global *mig)
                         &mig->mc_coreid, &mig->mc_core_threadid,
                         &mig->mc_apicid, NULL, NULL, NULL);
 
-    if ( curr != INVALID_VCPU )
+    if ( curr )
     {
         mig->mc_domid = curr->domain->domain_id;
         mig->mc_vcpuid = curr->vcpu_id;
diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c
index 4a07cfb18e..dd32712d2f 100644
--- a/xen/arch/x86/domain_page.c
+++ b/xen/arch/x86/domain_page.c
@@ -29,7 +29,7 @@  static inline struct vcpu *mapcache_current_vcpu(void)
      * When current isn't properly set up yet, this is equivalent to
      * running in an idle vCPU (callers must check for NULL).
      */
-    if ( v == INVALID_VCPU )
+    if ( !v )
         return NULL;
 
     /*
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 62adc9e2a8..1b6ca4a47d 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -707,9 +707,6 @@  void __init noreturn __start_xen(unsigned long mbi_p)
 
     /* Critical region without IDT or TSS.  Any fault is deadly! */
 
-    set_processor_id(0);
-    set_current(INVALID_VCPU); /* debug sanity. */
-    idle_vcpu[0] = current;
     init_shadow_spec_ctrl_state();
 
     percpu_init_areas();
diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c
index 3e828fe204..5020c4ad49 100644
--- a/xen/arch/x86/tboot.c
+++ b/xen/arch/x86/tboot.c
@@ -392,7 +392,7 @@  void tboot_shutdown(uint32_t shutdown_type)
      * During early boot, we can be called by panic before idle_vcpu[0] is
      * setup, but in that case we don't need to change page tables.
      */
-    if ( idle_vcpu[0] != INVALID_VCPU )
+    if ( idle_vcpu[0] )
         write_ptbase(idle_vcpu[0]);
 
     ((void(*)(void))(unsigned long)g_tboot_shared->shutdown_entry)();
diff --git a/xen/include/asm-x86/setup.h b/xen/include/asm-x86/setup.h
index 861d46d6ac..28257bc5c8 100644
--- a/xen/include/asm-x86/setup.h
+++ b/xen/include/asm-x86/setup.h
@@ -4,9 +4,6 @@ 
 #include <xen/multiboot.h>
 #include <asm/numa.h>
 
-/* vCPU pointer used prior to there being a valid one around */
-#define INVALID_VCPU ((struct vcpu *)0xccccccccccccc000UL)
-
 extern const char __2M_text_start[], __2M_text_end[];
 extern const char __2M_rodata_start[], __2M_rodata_end[];
 extern char __2M_init_start[], __2M_init_end[];