[RESEND PATCH 3/3] KVM: x86: Using cpuid structs in KVM

From: Nadav Amit
Date: Wed Sep 17 2014 - 08:55:11 EST


Using cpuid structs in KVM to eliminate cryptic code with many bit operations.
The code does not introduce functional changes.

Signed-off-by: Nadav Amit <namit@xxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 36 ++++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 38a0afe..a7479ab 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -18,6 +18,7 @@
#include <linux/uaccess.h>
#include <asm/user.h>
#include <asm/xsave.h>
+#include <asm/cpuid_def.h>
#include "cpuid.h"
#include "lapic.h"
#include "mmu.h"
@@ -357,16 +358,18 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
}
/* function 4 has additional index. */
case 4: {
- int i, cache_type;
+ int i;

entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
/* read more entries until cache_type is zero */
for (i = 1; ; ++i) {
+ union cpuid4_eax eax;
+
if (*nent >= maxnent)
goto out;

- cache_type = entry[i - 1].eax & 0x1f;
- if (!cache_type)
+ eax.full = entry[i - 1].eax;
+ if (!eax.split.cache_type)
break;
do_cpuid_1_ent(&entry[i], function, i);
entry[i].flags |=
@@ -423,16 +426,18 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
}
/* function 0xb has additional index. */
case 0xb: {
- int i, level_type;
+ int i;

entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
/* read more entries until level_type is zero */
for (i = 1; ; ++i) {
+ union cpuid11_ecx ecx;
+
if (*nent >= maxnent)
goto out;

- level_type = entry[i - 1].ecx & 0xff00;
- if (!level_type)
+ ecx.full = entry[i - 1].ecx;
+ if (!ecx.split.level_type)
break;
do_cpuid_1_ent(&entry[i], function, i);
entry[i].flags |=
@@ -505,13 +510,13 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
entry->eax = entry->ebx = entry->ecx = 0;
break;
case 0x80000008: {
- unsigned g_phys_as = (entry->eax >> 16) & 0xff;
- unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
- unsigned phys_as = entry->eax & 0xff;
+ union cpuid_8_8_eax eax;

- if (!g_phys_as)
- g_phys_as = phys_as;
- entry->eax = g_phys_as | (virt_as << 8);
+ eax.full = entry->eax;
+ eax.split.virt_as = max_t(int, eax.split.virt_as, 48);
+ if (!eax.split.guest_phys_as)
+ eax.split.guest_phys_as = eax.split.phys_as;
+ entry->eax = eax.full;
entry->ebx = entry->edx = 0;
break;
}
@@ -724,13 +729,16 @@ EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
+ union cpuid_8_8_eax eax;

best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
if (!best || best->eax < 0x80000008)
goto not_found;
best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
- if (best)
- return best->eax & 0xff;
+ if (best) {
+ eax.full = best->eax;
+ return eax.split.phys_as;
+ }
not_found:
return 36;
}
--
1.9.1

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