x86/asm: Rename FS/GS base helpers

They are currently named after the FSGSBASE instructions, but are not thin
wrappers around said instructions, and therefore do not accurately reflect the
logic they perform, especially when it comes to functioning safely in non
FSGSBASE context.

Rename them to {read,write}_{fs,gs}_base() to avoid confusion.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 4273d272e724b61ef5f7d431b7b994ca59cf749f..1cc85f4ab9012471cb66d2831baa99c33d0ef3b7 100644 (file)
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1581,9 +1581,9 @@ static void load_segments(struct vcpu *n)
 
     if ( !fs_gs_done && !compat )
     {
-        wrfsbase(n->arch.pv.fs_base);
-        wrgsshadow(n->arch.pv.gs_base_kernel);
-        wrgsbase(n->arch.pv.gs_base_user);
+        write_fs_base(n->arch.pv.fs_base);
+        write_gs_shadow(n->arch.pv.gs_base_kernel);
+        write_gs_base(n->arch.pv.gs_base_user);
 
         /* If in kernel mode then switch the GS bases around. */
         if ( (n->arch.flags & TF_kernel_mode) )
@@ -1707,9 +1707,9 @@ static void save_segments(struct vcpu *v)
 
     if ( !is_pv_32bit_vcpu(v) )
     {
-        unsigned long gs_base = rdgsbase();
+        unsigned long gs_base = read_gs_base();
 
-        v->arch.pv.fs_base = rdfsbase();
+        v->arch.pv.fs_base = read_fs_base();
         if ( v->arch.flags & TF_kernel_mode )
             v->arch.pv.gs_base_kernel = gs_base;
         else

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 998f33fb03bcf57ebd554ae95bc4b6d2efba3a5f..95d109f9622f57abbc04e8e214872cefb0ea81d2 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -512,12 +512,12 @@ static void vmx_save_guest_msrs(struct vcpu *v)
      * We cannot cache SHADOW_GS_BASE while the VCPU runs, as it can
      * be updated at any time via SWAPGS, which we cannot trap.
      */
-    v->arch.hvm.vmx.shadow_gs = rdgsshadow();
+    v->arch.hvm.vmx.shadow_gs = read_gs_shadow();
 }
 
 static void vmx_restore_guest_msrs(struct vcpu *v)
 {
-    wrgsshadow(v->arch.hvm.vmx.shadow_gs);
+    write_gs_shadow(v->arch.hvm.vmx.shadow_gs);
     wrmsrl(MSR_STAR,           v->arch.hvm.vmx.star);
     wrmsrl(MSR_LSTAR,          v->arch.hvm.vmx.lstar);
     wrmsrl(MSR_SYSCALL_MASK,   v->arch.hvm.vmx.sfmask);
@@ -2958,7 +2958,7 @@ static int vmx_msr_read_intercept(unsigned int msr, uint64_t *msr_content)
         break;
 
     case MSR_SHADOW_GS_BASE:
-        *msr_content = rdgsshadow();
+        *msr_content = read_gs_shadow();
         break;
 
     case MSR_STAR:
@@ -3182,7 +3182,7 @@ static int vmx_msr_write_intercept(unsigned int msr, uint64_t msr_content)
         else if ( msr == MSR_GS_BASE )
             __vmwrite(GUEST_GS_BASE, msr_content);
         else
-            wrgsshadow(msr_content);
+            write_gs_shadow(msr_content);
 
         break;
 

diff --git a/xen/arch/x86/pv/domain.c b/xen/arch/x86/pv/domain.c
index 44e4ea2582701a3446d5fe218b11ec02819ea257..663e76c773037bef38d92ecd6f8df9b278d60b3d 100644 (file)
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -452,7 +452,7 @@ void toggle_guest_mode(struct vcpu *v)
      * Update the cached value of the GS base about to become inactive, as a
      * subsequent context switch won't bother re-reading it.
      */
-    gs_base = rdgsbase();
+    gs_base = read_gs_base();
     if ( v->arch.flags & TF_kernel_mode )
         v->arch.pv.gs_base_kernel = gs_base;
     else

diff --git a/xen/arch/x86/pv/emul-priv-op.c b/xen/arch/x86/pv/emul-priv-op.c
index 61071ae03a41b1290dc4be145758c06a07f172f5..6be72efb5e55e8f9c6590b77e8242d0df71e3e20 100644 (file)
--- a/xen/arch/x86/pv/emul-priv-op.c
+++ b/xen/arch/x86/pv/emul-priv-op.c
@@ -540,10 +540,10 @@ static int read_segment(enum x86_segment seg,
             reg->base = 0;
             break;
         case x86_seg_fs:
-            reg->base = rdfsbase();
+            reg->base = read_fs_base();
             break;
         case x86_seg_gs:
-            reg->base = rdgsbase();
+            reg->base = read_gs_base();
             break;
         }
 
@@ -900,13 +900,13 @@ static int read_msr(unsigned int reg, uint64_t *val,
     case MSR_FS_BASE:
         if ( is_pv_32bit_domain(currd) )
             break;
-        *val = rdfsbase();
+        *val = read_fs_base();
         return X86EMUL_OKAY;
 
     case MSR_GS_BASE:
         if ( is_pv_32bit_domain(currd) )
             break;
-        *val = rdgsbase();
+        *val = read_gs_base();
         return X86EMUL_OKAY;
 
     case MSR_SHADOW_GS_BASE:
@@ -1024,19 +1024,19 @@ static int write_msr(unsigned int reg, uint64_t val,
     case MSR_FS_BASE:
         if ( is_pv_32bit_domain(currd) || !is_canonical_address(val) )
             break;
-        wrfsbase(val);
+        write_fs_base(val);
         return X86EMUL_OKAY;
 
     case MSR_GS_BASE:
         if ( is_pv_32bit_domain(currd) || !is_canonical_address(val) )
             break;
-        wrgsbase(val);
+        write_gs_base(val);
         return X86EMUL_OKAY;
 
     case MSR_SHADOW_GS_BASE:
         if ( is_pv_32bit_domain(currd) || !is_canonical_address(val) )
             break;
-        wrgsshadow(val);
+        write_gs_shadow(val);
         curr->arch.pv.gs_base_user = val;
         return X86EMUL_OKAY;
 

diff --git a/xen/arch/x86/pv/misc-hypercalls.c b/xen/arch/x86/pv/misc-hypercalls.c
index b353972e3db9e8c6b62167fd736d86ee22a03246..3a4e4aa4603e720928233b680e004e40838eeb71 100644 (file)
--- a/xen/arch/x86/pv/misc-hypercalls.c
+++ b/xen/arch/x86/pv/misc-hypercalls.c
@@ -192,7 +192,7 @@ long do_set_segment_base(unsigned int which, unsigned long base)
     {
     case SEGBASE_FS:
         if ( is_canonical_address(base) )
-            wrfsbase(base);
+            write_fs_base(base);
         else
             ret = -EINVAL;
         break;
@@ -200,7 +200,7 @@ long do_set_segment_base(unsigned int which, unsigned long base)
     case SEGBASE_GS_USER:
         if ( is_canonical_address(base) )
         {
-            wrgsshadow(base);
+            write_gs_shadow(base);
             v->arch.pv.gs_base_user = base;
         }
         else
@@ -209,7 +209,7 @@ long do_set_segment_base(unsigned int which, unsigned long base)
 
     case SEGBASE_GS_KERNEL:
         if ( is_canonical_address(base) )
-            wrgsbase(base);
+            write_gs_base(base);
         else
             ret = -EINVAL;
         break;
@@ -258,7 +258,7 @@ long do_set_segment_base(unsigned int which, unsigned long base)
                        : [flat] "r" (FLAT_USER_DS32) );
 
         /* Update the cache of the inactive base, as read from the GDT/LDT. */
-        v->arch.pv.gs_base_user = rdgsbase();
+        v->arch.pv.gs_base_user = read_gs_base();
 
         asm volatile ( safe_swapgs );
         break;

diff --git a/xen/arch/x86/x86_64/traps.c b/xen/arch/x86/x86_64/traps.c
index fd049c5e14ff922054f441ab0b92fbe7a55b612e..b1ef40a8462a1c7c5b433ff838b95d7d6de1914e 100644 (file)
--- a/xen/arch/x86/x86_64/traps.c
+++ b/xen/arch/x86/x86_64/traps.c
@@ -44,9 +44,9 @@ static void read_registers(struct cpu_user_regs *regs, unsigned long crs[8])
     crs[3] = read_cr3();
     crs[4] = read_cr4();
     read_sregs(regs);
-    crs[5] = rdfsbase();
-    crs[6] = rdgsbase();
-    crs[7] = rdgsshadow();
+    crs[5] = read_fs_base();
+    crs[6] = read_gs_base();
+    crs[7] = read_gs_shadow();
 }
 
 static void _show_registers(

diff --git a/xen/include/asm-x86/msr.h b/xen/include/asm-x86/msr.h
index 5c44c79600333db25b4db0ce41053ca4d5b241cc..5e141ac5a52240b3545af7a050610e36fa63d965 100644 (file)
--- a/xen/include/asm-x86/msr.h
+++ b/xen/include/asm-x86/msr.h
@@ -156,7 +156,7 @@ static inline unsigned long __rdgsbase(void)
     return base;
 }
 
-static inline unsigned long rdfsbase(void)
+static inline unsigned long read_fs_base(void)
 {
     unsigned long base;
 
@@ -168,7 +168,7 @@ static inline unsigned long rdfsbase(void)
     return base;
 }
 
-static inline unsigned long rdgsbase(void)
+static inline unsigned long read_gs_base(void)
 {
     unsigned long base;
 
@@ -180,7 +180,7 @@ static inline unsigned long rdgsbase(void)
     return base;
 }
 
-static inline unsigned long rdgsshadow(void)
+static inline unsigned long read_gs_shadow(void)
 {
     unsigned long base;
 
@@ -196,7 +196,7 @@ static inline unsigned long rdgsshadow(void)
     return base;
 }
 
-static inline void wrfsbase(unsigned long base)
+static inline void write_fs_base(unsigned long base)
 {
     if ( read_cr4() & X86_CR4_FSGSBASE )
 #ifdef HAVE_AS_FSGSBASE
@@ -208,7 +208,7 @@ static inline void wrfsbase(unsigned long base)
         wrmsrl(MSR_FS_BASE, base);
 }
 
-static inline void wrgsbase(unsigned long base)
+static inline void write_gs_base(unsigned long base)
 {
     if ( read_cr4() & X86_CR4_FSGSBASE )
 #ifdef HAVE_AS_FSGSBASE
@@ -220,7 +220,7 @@ static inline void wrgsbase(unsigned long base)
         wrmsrl(MSR_GS_BASE, base);
 }
 
-static inline void wrgsshadow(unsigned long base)
+static inline void write_gs_shadow(unsigned long base)
 {
     if ( read_cr4() & X86_CR4_FSGSBASE )
     {