[PATCH v3 05/22] x86/xstate: drop xstate_offsets[] and xstate_sizes[]

[Jan Beulich <jbeulich@suse.com>]

They're redundant with respective fields from the raw CPUID policy; no
need to keep two copies of the same data. This also breaks
recalculate_xstate()'s dependency on xstate_init(), allowing host CPUID
policy calculation to be moved together with that of the raw one (which
a subsequent change will require anyway).

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -498,6 +498,8 @@ void identify_cpu(struct cpuinfo_x86 *c)
 	}
 
 	/* Now the feature flags better reflect actual CPU features! */
+	if (c == &boot_cpu_data)
+		init_host_cpuid();
 
 	xstate_init(c);
 
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -170,32 +170,32 @@ static void recalculate_xstate(struct cp
     {
         xstates |= X86_XCR0_YMM;
         xstate_size = max(xstate_size,
-                          xstate_offsets[X86_XCR0_YMM_POS] +
-                          xstate_sizes[X86_XCR0_YMM_POS]);
+                          xstate_offset(X86_XCR0_YMM_POS) +
+                          xstate_size(X86_XCR0_YMM_POS));
     }
 
     if ( p->feat.mpx )
     {
         xstates |= X86_XCR0_BNDREGS | X86_XCR0_BNDCSR;
         xstate_size = max(xstate_size,
-                          xstate_offsets[X86_XCR0_BNDCSR_POS] +
-                          xstate_sizes[X86_XCR0_BNDCSR_POS]);
+                          xstate_offset(X86_XCR0_BNDCSR_POS) +
+                          xstate_size(X86_XCR0_BNDCSR_POS));
     }
 
     if ( p->feat.avx512f )
     {
         xstates |= X86_XCR0_OPMASK | X86_XCR0_ZMM | X86_XCR0_HI_ZMM;
         xstate_size = max(xstate_size,
-                          xstate_offsets[X86_XCR0_HI_ZMM_POS] +
-                          xstate_sizes[X86_XCR0_HI_ZMM_POS]);
+                          xstate_offset(X86_XCR0_HI_ZMM_POS) +
+                          xstate_size(X86_XCR0_HI_ZMM_POS));
     }
 
     if ( p->feat.pku )
     {
         xstates |= X86_XCR0_PKRU;
         xstate_size = max(xstate_size,
-                          xstate_offsets[X86_XCR0_PKRU_POS] +
-                          xstate_sizes[X86_XCR0_PKRU_POS]);
+                          xstate_offset(X86_XCR0_PKRU_POS) +
+                          xstate_size(X86_XCR0_PKRU_POS));
     }
 
     p->xstate.max_size  =  xstate_size;
@@ -218,8 +218,8 @@ static void recalculate_xstate(struct cp
         if ( !(xstates & curr_xstate) )
             continue;
 
-        p->xstate.comp[i].size   = xstate_sizes[i];
-        p->xstate.comp[i].offset = xstate_offsets[i];
+        p->xstate.comp[i].size   = xstate_size(i);
+        p->xstate.comp[i].offset = xstate_offset(i);
         p->xstate.comp[i].xss    = curr_xstate & XSTATE_XSAVES_ONLY;
         p->xstate.comp[i].align  = curr_xstate & xstate_align;
     }
@@ -531,10 +531,16 @@ static void __init calculate_hvm_def_pol
     x86_cpuid_policy_shrink_max_leaves(p);
 }
 
-void __init init_guest_cpuid(void)
+void __init init_host_cpuid(void)
 {
     calculate_raw_policy();
     calculate_host_policy();
+}
+
+void __init init_guest_cpuid(void)
+{
+    /* Do this a 2nd time to account for setup_{clear,force}_cpu_cap() uses. */
+    calculate_host_policy();
 
     if ( IS_ENABLED(CONFIG_PV) )
     {
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -9,6 +9,7 @@
 #include <xen/percpu.h>
 #include <xen/sched.h>
 #include <xen/xvmalloc.h>
+#include <asm/cpuid.h>
 #include <asm/current.h>
 #include <asm/processor.h>
 #include <asm/hvm/support.h>
@@ -26,8 +27,6 @@ static u32 __read_mostly xsave_cntxt_siz
 /* A 64-bit bitmask of the XSAVE/XRSTOR features supported by processor. */
 u64 __read_mostly xfeature_mask;
 
-unsigned int *__read_mostly xstate_offsets;
-unsigned int *__read_mostly xstate_sizes;
 u64 __read_mostly xstate_align;
 static unsigned int __read_mostly xstate_features;
 
@@ -93,34 +92,19 @@ static int setup_xstate_features(bool bs
     unsigned int leaf, eax, ebx, ecx, edx;
 
     if ( bsp )
-    {
         xstate_features = flsl(xfeature_mask);
-        xstate_offsets = xzalloc_array(unsigned int, xstate_features);
-        if ( !xstate_offsets )
-            return -ENOMEM;
-
-        xstate_sizes = xzalloc_array(unsigned int, xstate_features);
-        if ( !xstate_sizes )
-            return -ENOMEM;
-    }
 
     for ( leaf = 2; leaf < xstate_features; leaf++ )
     {
-        if ( bsp )
-        {
-            cpuid_count(XSTATE_CPUID, leaf, &xstate_sizes[leaf],
-                        &xstate_offsets[leaf], &ecx, &edx);
-            if ( ecx & XSTATE_ALIGN64 )
-                __set_bit(leaf, &xstate_align);
-        }
+        cpuid_count(XSTATE_CPUID, leaf, &eax,
+                    &ebx, &ecx, &edx);
+        BUG_ON(eax != xstate_size(leaf));
+        BUG_ON(ebx != xstate_offset(leaf));
+
+        if ( bsp && (ecx & XSTATE_ALIGN64) )
+            __set_bit(leaf, &xstate_align);
         else
-        {
-            cpuid_count(XSTATE_CPUID, leaf, &eax,
-                        &ebx, &ecx, &edx);
-            BUG_ON(eax != xstate_sizes[leaf]);
-            BUG_ON(ebx != xstate_offsets[leaf]);
             BUG_ON(!(ecx & XSTATE_ALIGN64) != !test_bit(leaf, &xstate_align));
-        }
     }
 
     return 0;
@@ -150,7 +134,7 @@ static void setup_xstate_comp(uint16_t *
             if ( test_bit(i, &xstate_align) )
                 offset = ROUNDUP(offset, 64);
             comp_offsets[i] = offset;
-            offset += xstate_sizes[i];
+            offset += xstate_size(i);
         }
     }
     ASSERT(offset <= xsave_cntxt_size);
@@ -213,10 +197,10 @@ void expand_xsave_states(struct vcpu *v,
          * comp_offsets[] information, something is very broken.
          */
         BUG_ON(!comp_offsets[index]);
-        BUG_ON((xstate_offsets[index] + xstate_sizes[index]) > size);
+        BUG_ON((xstate_offset(index) + xstate_size(index)) > size);
 
-        memcpy(dest + xstate_offsets[index], src + comp_offsets[index],
-               xstate_sizes[index]);
+        memcpy(dest + xstate_offset(index), src + comp_offsets[index],
+               xstate_size(index));
 
         valid &= ~feature;
     }
@@ -279,10 +263,10 @@ void compress_xsave_states(struct vcpu *
          * comp_offset[] information, something is very broken.
          */
         BUG_ON(!comp_offsets[index]);
-        BUG_ON((xstate_offsets[index] + xstate_sizes[index]) > size);
+        BUG_ON((xstate_offset(index) + xstate_size(index)) > size);
 
-        memcpy(dest + comp_offsets[index], src + xstate_offsets[index],
-               xstate_sizes[index]);
+        memcpy(dest + comp_offsets[index], src + xstate_offset(index),
+               xstate_size(index));
 
         valid &= ~feature;
     }
@@ -516,8 +500,8 @@ int xstate_alloc_save_area(struct vcpu *
         unsigned int i;
 
         for ( size = 0, i = 2; i < xstate_features; ++i )
-            if ( size < xstate_sizes[i] )
-                size = xstate_sizes[i];
+            if ( size < xstate_size(i) )
+                size = xstate_size(i);
         size += XSTATE_AREA_MIN_SIZE;
     }
 
@@ -559,9 +543,9 @@ int xstate_update_save_area(struct vcpu
     for ( size = old = XSTATE_AREA_MIN_SIZE, i = 2; i < xstate_features; ++i )
     {
         if ( xcr0_max & (1ul << i) )
-            size = max(size, xstate_offsets[i] + xstate_sizes[i]);
+            size = max(size, xstate_offset(i) + xstate_size(i));
         if ( v->arch.xcr0_accum & (1ul << i) )
-            old = max(old, xstate_offsets[i] + xstate_sizes[i]);
+            old = max(old, xstate_offset(i) + xstate_size(i));
     }
 
     save_area = _xvrealloc(v->arch.xsave_area, size, __alignof(*save_area));
@@ -819,7 +803,7 @@ uint64_t read_bndcfgu(void)
               : "=m" (*xstate)
               : "a" (X86_XCR0_BNDCSR), "d" (0), "D" (xstate) );
 
-        bndcsr = (void *)xstate + xstate_offsets[X86_XCR0_BNDCSR_POS];
+        bndcsr = (void *)xstate + xstate_offset(X86_XCR0_BNDCSR_POS);
     }
 
     if ( cr0 & X86_CR0_TS )
--- a/xen/include/asm-x86/cpuid.h
+++ b/xen/include/asm-x86/cpuid.h
@@ -16,6 +16,7 @@
 extern const uint32_t known_features[FSCAPINTS];
 extern const uint32_t special_features[FSCAPINTS];
 
+void init_host_cpuid(void);
 void init_guest_cpuid(void);
 
 /*
--- a/xen/include/asm-x86/xstate.h
+++ b/xen/include/asm-x86/xstate.h
@@ -44,8 +44,9 @@ extern uint32_t mxcsr_mask;
 
 extern u64 xfeature_mask;
 extern u64 xstate_align;
-extern unsigned int *xstate_offsets;
-extern unsigned int *xstate_sizes;
+
+#define xstate_offset(n) (raw_cpuid_policy.xstate.comp[n].offset)
+#define xstate_size(n)   (raw_cpuid_policy.xstate.comp[n].size)
 
 /* extended state save area */
 struct __attribute__((aligned (64))) xsave_struct