[PATCH 0/2] hw/i386: Cleanups around kvmclock_create()

[PATCH 0/2] hw/i386: Cleanups around kvmclock_create()

[Philippe Mathieu-Daudé]

After removing the kvmclock_create() stub we restrict
"hw/kvm/clock.h" to x86, the single arch implementing /
using this.

Philippe Mathieu-Daudé (2):
  hw/i386: Remove unuseful kvmclock_create() stub
  hw/i386: Rename 'hw/kvm/clock.h' -> 'hw/i386/kvm/clock.h'

 {include/hw => hw/i386}/kvm/clock.h | 14 ++------------
 hw/i386/kvm/clock.c                 |  6 ++++--
 hw/i386/microvm.c                   |  6 ++++--
 hw/i386/pc_piix.c                   |  4 ++--
 hw/i386/pc_q35.c                    |  6 ++++--
 5 files changed, 16 insertions(+), 20 deletions(-)
 rename {include/hw => hw/i386}/kvm/clock.h (65%)

-- 
2.38.1

[PATCH 1/2] hw/i386: Remove unuseful kvmclock_create() stub

[Philippe Mathieu-Daudé]

We shouldn't call kvmclock_create() when KVM is not available
or disabled:
 - check for kvm_enabled() before calling it
 - assert KVM is enabled once called
Since the call is elided when KVM is not available, we can
remove the stub (it is never compiled).

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/kvm/clock.h | 10 ----------
 hw/i386/kvm/clock.c    |  4 +++-
 hw/i386/microvm.c      |  4 +++-
 hw/i386/pc_piix.c      |  2 +-
 hw/i386/pc_q35.c       |  4 +++-
 5 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/include/hw/kvm/clock.h b/include/hw/kvm/clock.h
index 7994071c4f..3efe0a871c 100644
--- a/include/hw/kvm/clock.h
+++ b/include/hw/kvm/clock.h
@@ -13,16 +13,6 @@
 #ifndef HW_KVM_CLOCK_H
 #define HW_KVM_CLOCK_H
 
-#ifdef CONFIG_KVM
-
 void kvmclock_create(bool create_always);
 
-#else /* CONFIG_KVM */
-
-static inline void kvmclock_create(bool create_always)
-{
-}
-
-#endif /* !CONFIG_KVM */
-
 #endif
diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c
index df70b4a033..0824c6d313 100644
--- a/hw/i386/kvm/clock.c
+++ b/hw/i386/kvm/clock.c
@@ -332,8 +332,10 @@ void kvmclock_create(bool create_always)
 {
     X86CPU *cpu = X86_CPU(first_cpu);
 
-    if (!kvm_enabled() || !kvm_has_adjust_clock())
+    assert(kvm_enabled());
+    if (!kvm_has_adjust_clock()) {
         return;
+    }
 
     if (create_always ||
         cpu->env.features[FEAT_KVM] & ((1ULL << KVM_FEATURE_CLOCKSOURCE) |
diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 7227a2156c..6b762bc18e 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -180,7 +180,9 @@ static void microvm_devices_init(MicrovmMachineState *mms)
         x86ms->ioapic2 = ioapic_init_secondary(gsi_state);
     }
 
-    kvmclock_create(true);
+    if (kvm_enabled()) {
+        kvmclock_create(true);
+    }
 
     mms->virtio_irq_base = 5;
     mms->virtio_num_transports = 8;
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 44146e6ff5..715c063eec 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -193,7 +193,7 @@ static void pc_init1(MachineState *machine,
     pc_machine_init_sgx_epc(pcms);
     x86_cpus_init(x86ms, pcmc->default_cpu_version);
 
-    if (pcmc->kvmclock_enabled) {
+    if (kvm_enabled() && pcmc->kvmclock_enabled) {
         kvmclock_create(pcmc->kvmclock_create_always);
     }
 
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index a9a59ed42b..a0553f70f7 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -184,7 +184,9 @@ static void pc_q35_init(MachineState *machine)
     pc_machine_init_sgx_epc(pcms);
     x86_cpus_init(x86ms, pcmc->default_cpu_version);
 
-    kvmclock_create(pcmc->kvmclock_create_always);
+    if (kvm_enabled()) {
+        kvmclock_create(pcmc->kvmclock_create_always);
+    }
 
     /* pci enabled */
     if (pcmc->pci_enabled) {
-- 
2.38.1

Re: [PATCH 1/2] hw/i386: Remove unuseful kvmclock_create() stub

[Alex Bennée]

Philippe Mathieu-Daudé <philmd@linaro.org> writes:

> We shouldn't call kvmclock_create() when KVM is not available
> or disabled:
>  - check for kvm_enabled() before calling it
>  - assert KVM is enabled once called
> Since the call is elided when KVM is not available, we can
> remove the stub (it is never compiled).
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

[RFC PATCH 2/2] hw/i386: Rename 'hw/kvm/clock.h' -> 'hw/i386/kvm/clock.h'

[Philippe Mathieu-Daudé]

kvmclock_create() is only implemented in hw/i386/kvm/clock.h.
Restrict the "hw/kvm/clock.h" header to i386 by moving it to
hw/i386/.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
RFC: No other arch had to implement this for 12 years,
     safe enough to restrict to x86?
---
 {include/hw => hw/i386}/kvm/clock.h | 4 ++--
 hw/i386/kvm/clock.c                 | 2 +-
 hw/i386/microvm.c                   | 2 +-
 hw/i386/pc_piix.c                   | 2 +-
 hw/i386/pc_q35.c                    | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)
 rename {include/hw => hw/i386}/kvm/clock.h (85%)

diff --git a/include/hw/kvm/clock.h b/hw/i386/kvm/clock.h
similarity index 85%
rename from include/hw/kvm/clock.h
rename to hw/i386/kvm/clock.h
index 3efe0a871c..401c7e445b 100644
--- a/include/hw/kvm/clock.h
+++ b/hw/i386/kvm/clock.h
@@ -10,8 +10,8 @@
  * See the COPYING file in the top-level directory.
  */
 
-#ifndef HW_KVM_CLOCK_H
-#define HW_KVM_CLOCK_H
+#ifndef HW_I386_KVM_CLOCK_H
+#define HW_I386_KVM_CLOCK_H
 
 void kvmclock_create(bool create_always);
 
diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c
index 0824c6d313..34348a3324 100644
--- a/hw/i386/kvm/clock.c
+++ b/hw/i386/kvm/clock.c
@@ -22,7 +22,7 @@
 #include "kvm/kvm_i386.h"
 #include "migration/vmstate.h"
 #include "hw/sysbus.h"
-#include "hw/kvm/clock.h"
+#include "hw/i386/kvm/clock.h"
 #include "hw/qdev-properties.h"
 #include "qapi/error.h"
 
diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 6b762bc18e..8deeb62774 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -32,7 +32,7 @@
 
 #include "hw/loader.h"
 #include "hw/irq.h"
-#include "hw/kvm/clock.h"
+#include "hw/i386/kvm/clock.h"
 #include "hw/i386/microvm.h"
 #include "hw/i386/x86.h"
 #include "target/i386/cpu.h"
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 715c063eec..85fe41327c 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -46,7 +46,7 @@
 #include "hw/ide/piix.h"
 #include "hw/irq.h"
 #include "sysemu/kvm.h"
-#include "hw/kvm/clock.h"
+#include "hw/i386/kvm/clock.h"
 #include "hw/sysbus.h"
 #include "hw/i2c/smbus_eeprom.h"
 #include "exec/memory.h"
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index a0553f70f7..9e6602dfde 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -35,7 +35,7 @@
 #include "hw/i2c/smbus_eeprom.h"
 #include "hw/rtc/mc146818rtc.h"
 #include "sysemu/kvm.h"
-#include "hw/kvm/clock.h"
+#include "hw/i386/kvm/clock.h"
 #include "hw/pci-host/q35.h"
 #include "hw/pci/pcie_port.h"
 #include "hw/qdev-properties.h"
-- 
2.38.1

Re: [RFC PATCH 2/2] hw/i386: Rename 'hw/kvm/clock.h' -> 'hw/i386/kvm/clock.h'

[Alex Bennée]

Philippe Mathieu-Daudé <philmd@linaro.org> writes:

> kvmclock_create() is only implemented in hw/i386/kvm/clock.h.
> Restrict the "hw/kvm/clock.h" header to i386 by moving it to
> hw/i386/.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
> RFC: No other arch had to implement this for 12 years,
>      safe enough to restrict to x86?

Importantly the implementation is certainly in i386 only:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro