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[Qemu-devel] [RFC 02/12] target-i386: Don't set any KVM flag by default
From: |
Eduardo Habkost |
Subject: |
[Qemu-devel] [RFC 02/12] target-i386: Don't set any KVM flag by default if KVM is disabled |
Date: |
Wed, 9 Jan 2013 16:53:42 -0200 |
This is a cleanup that tries to solve two small issues:
- We don't need a separate kvm_pv_eoi_features variable just to keep a
constant calculated at compile-time, and this style would require
adding a separate variable (that's declared twice because of the
CONFIG_KVM ifdef) for each feature that's going to be enabled/disable
by machine-type compat code.
- The pc-1.3 code is setting the kvm_pv_eoi flag on cpuid_kvm_features
even when KVM is disabled at runtime. This small incosistency in
the cpuid_kvm_features field isn't a problem today because
cpuid_kvm_features is ignored by the TCG code, but it may cause
unexpected problems later when refactoring the CPUID handling code.
This patch eliminates the kvm_pv_eoi_features variable and simply uses
kvm_enabled() inside the enable_kvm_pv_eoi() compat function, so it
enables kvm_pv_eoi only if KVM is enabled. I believe this makes the
behavior of enable_kvm_pv_eoi() clearer and easier to understand.
Signed-off-by: Eduardo Habkost <address@hidden>
---
Cc: address@hidden
Cc: Michael S. Tsirkin <address@hidden>
Cc: Gleb Natapov <address@hidden>
Cc: Marcelo Tosatti <address@hidden>
Changes v2:
- Coding style fix
Changes v3:
- Eliminate #ifdef by using the fake KVM_FEATURE_PV_EOI #define
Changes v4:
- Check kvm_enabled() when actually using kvm_default_features
- Eliminate Yet Another #ifdef by using the fake KVM_FEATURE_*
#defines on kvm_default_features initialization
---
target-i386/cpu.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index e4dc370..57a22b7 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -206,22 +206,16 @@ typedef struct model_features_t {
int check_cpuid = 0;
int enforce_cpuid = 0;
-#if defined(CONFIG_KVM)
static uint32_t kvm_default_features = (1 << KVM_FEATURE_CLOCKSOURCE) |
(1 << KVM_FEATURE_NOP_IO_DELAY) |
(1 << KVM_FEATURE_CLOCKSOURCE2) |
(1 << KVM_FEATURE_ASYNC_PF) |
(1 << KVM_FEATURE_STEAL_TIME) |
(1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);
-static const uint32_t kvm_pv_eoi_features = (0x1 << KVM_FEATURE_PV_EOI);
-#else
-static uint32_t kvm_default_features = 0;
-static const uint32_t kvm_pv_eoi_features = 0;
-#endif
void enable_kvm_pv_eoi(void)
{
- kvm_default_features |= kvm_pv_eoi_features;
+ kvm_default_features |= (1UL << KVM_FEATURE_PV_EOI);
}
void host_cpuid(uint32_t function, uint32_t count,
@@ -1343,13 +1337,15 @@ static int cpu_x86_parse_featurestr(x86_def_t
*x86_cpu_def, char *features)
unsigned int i;
char *featurestr; /* Single 'key=value" string being parsed */
/* Features to be added */
- FeatureWordArray plus_features = {
- [FEAT_KVM] = kvm_default_features,
- };
+ FeatureWordArray plus_features = { 0 };
/* Features to be removed */
FeatureWordArray minus_features = { 0 };
uint32_t numvalue;
+ if (kvm_enabled()) {
+ plus_features[FEAT_KVM] = kvm_default_features;
+ }
+
add_flagname_to_bitmaps("hypervisor", plus_features);
featurestr = features ? strtok(features, ",") : NULL;
--
1.7.11.7
- [Qemu-devel] [RFC 09/12] pc: Set fw_cfg data based on APIC ID calculation, (continued)
- [Qemu-devel] [RFC 09/12] pc: Set fw_cfg data based on APIC ID calculation, Eduardo Habkost, 2013/01/09
- [Qemu-devel] [RFC 12/12] pc: Generate APIC IDs according to CPU topology, Eduardo Habkost, 2013/01/09
- [Qemu-devel] [RFC 04/12] kvm: Create kvm_arch_vcpu_id() function, Eduardo Habkost, 2013/01/09
- [Qemu-devel] [RFC 07/12] target-i386/cpu: Introduce apic_id_for_cpu() function, Eduardo Habkost, 2013/01/09
- [Qemu-devel] [RFC 10/12] tests: Support target-specific unit tests, Eduardo Habkost, 2013/01/09
- [Qemu-devel] [RFC 02/12] target-i386: Don't set any KVM flag by default if KVM is disabled,
Eduardo Habkost <=
- [Qemu-devel] [RFC 11/12] target-i386: Topology & APIC ID utility functions, Eduardo Habkost, 2013/01/09
- Re: [Qemu-devel] [RFC 00/12] target-i386: Fix APIC-ID-based topology (v4), Eduardo Habkost, 2013/01/17