diff mbox series

[v2,1/2] x86: make VMware support optional

Message ID 20201202211949.17730-1-info@metux.net (mailing list archive)
State New
Headers show
Series [v2,1/2] x86: make VMware support optional | expand

Commit Message

Enrico Weigelt, metux IT consult Dec. 2, 2020, 9:19 p.m. UTC
Make it possible to opt-out from VMware support, for minimized kernels
that never will be run under Vmware (eg. high-density virtualization
or embedded systems).

Average distro kernel will leave it on, therefore default to y.

Signed-off-by: Enrico Weigelt <info@metux.net>
---
 arch/x86/Kconfig                 | 11 +++++++++++
 arch/x86/kernel/cpu/Makefile     |  4 +++-
 arch/x86/kernel/cpu/hypervisor.c |  2 ++
 drivers/input/mouse/Kconfig      |  2 +-
 drivers/misc/Kconfig             |  2 +-
 drivers/ptp/Kconfig              |  2 +-
 6 files changed, 19 insertions(+), 4 deletions(-)

Comments

Randy Dunlap Dec. 2, 2020, 9:59 p.m. UTC | #1
On 12/2/20 1:19 PM, Enrico Weigelt, metux IT consult wrote:
> Make it possible to opt-out from VMware support, for minimized kernels
> that never will be run under Vmware (eg. high-density virtualization
> or embedded systems).
> 
> Average distro kernel will leave it on, therefore default to y.
> 
> Signed-off-by: Enrico Weigelt <info@metux.net>
> ---
>  arch/x86/Kconfig                 | 11 +++++++++++
>  arch/x86/kernel/cpu/Makefile     |  4 +++-
>  arch/x86/kernel/cpu/hypervisor.c |  2 ++
>  drivers/input/mouse/Kconfig      |  2 +-
>  drivers/misc/Kconfig             |  2 +-
>  drivers/ptp/Kconfig              |  2 +-
>  6 files changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index f6946b81f74a..eff12460cb3c 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -801,6 +801,17 @@ config X86_HV_CALLBACK_VECTOR
>  
>  source "arch/x86/xen/Kconfig"
>  
> +config VMWARE_GUEST
> +	bool "VMware Guest support"
> +	default y
> +	help
> +	  This option enables several optimizations for running under the
> +	  VMware hypervisor.
> +
> +	  Disabling it saves a few kb, for stripped down kernels eg. in high

	                           kB or KiB or even KB, but not kb
	                                                         e.g.

> +	  density virtualization or embedded systems running (para)virtualized
> +	  workloads.
> +
>  config KVM_GUEST
>  	bool "KVM Guest support (including kvmclock)"
>  	depends on PARAVIRT
Borislav Petkov Dec. 3, 2020, 7:46 a.m. UTC | #2
On Wed, Dec 02, 2020 at 10:19:48PM +0100, Enrico Weigelt, metux IT consult wrote:
> Make it possible to opt-out from VMware support, for minimized kernels
> that never will be run under Vmware (eg. high-density virtualization
> or embedded systems).
> 
> Average distro kernel will leave it on, therefore default to y.
> 
> Signed-off-by: Enrico Weigelt <info@metux.net>
> ---
>  arch/x86/Kconfig                 | 11 +++++++++++
>  arch/x86/kernel/cpu/Makefile     |  4 +++-
>  arch/x86/kernel/cpu/hypervisor.c |  2 ++
>  drivers/input/mouse/Kconfig      |  2 +-
>  drivers/misc/Kconfig             |  2 +-
>  drivers/ptp/Kconfig              |  2 +-
>  6 files changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index f6946b81f74a..eff12460cb3c 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -801,6 +801,17 @@ config X86_HV_CALLBACK_VECTOR
>  
>  source "arch/x86/xen/Kconfig"
>  
> +config VMWARE_GUEST
> +	bool "VMware Guest support"
> +	default y
> +	help
> +	  This option enables several optimizations for running under the
> +	  VMware hypervisor.
> +
> +	  Disabling it saves a few kb, for stripped down kernels eg. in high

I was actually expecting for you to do your own measurements and show data.
Anyway, I did it for you:

   text    data     bss     dec     hex filename
15949304        127806978       36597916        180354198       abffc96 vmlinux.before
15947650        127802430       36602012        180352092       abff45c vmlinux.after

this is with my .config.

How much is it with a stripped down kernel? I bet it is even less. Which
makes this whole effort not worth it...

Also, when you send a new version of your patches, please rework *all*
review feedback you've received on the previous one.

Thx.
diff mbox series

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f6946b81f74a..eff12460cb3c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -801,6 +801,17 @@  config X86_HV_CALLBACK_VECTOR
 
 source "arch/x86/xen/Kconfig"
 
+config VMWARE_GUEST
+	bool "VMware Guest support"
+	default y
+	help
+	  This option enables several optimizations for running under the
+	  VMware hypervisor.
+
+	  Disabling it saves a few kb, for stripped down kernels eg. in high
+	  density virtualization or embedded systems running (para)virtualized
+	  workloads.
+
 config KVM_GUEST
 	bool "KVM Guest support (including kvmclock)"
 	depends on PARAVIRT
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 93792b457b81..a615b0152bf0 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -51,7 +51,9 @@  obj-$(CONFIG_X86_CPU_RESCTRL)		+= resctrl/
 
 obj-$(CONFIG_X86_LOCAL_APIC)		+= perfctr-watchdog.o
 
-obj-$(CONFIG_HYPERVISOR_GUEST)		+= vmware.o hypervisor.o mshyperv.o
+obj-$(CONFIG_HYPERVISOR_GUEST)		+= hypervisor.o mshyperv.o
+obj-$(CONFIG_VMWARE_GUEST)		+= vmware.o
+
 obj-$(CONFIG_ACRN_GUEST)		+= acrn.o
 
 ifdef CONFIG_X86_FEATURE_NAMES
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index 553bfbfc3a1b..c0e770a224aa 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -34,7 +34,9 @@  static const __initconst struct hypervisor_x86 * const hypervisors[] =
 #ifdef CONFIG_XEN_PVHVM
 	&x86_hyper_xen_hvm,
 #endif
+#ifdef CONFIG_VMWARE_GUEST
 	&x86_hyper_vmware,
+#endif
 	&x86_hyper_ms_hyperv,
 #ifdef CONFIG_KVM_GUEST
 	&x86_hyper_kvm,
diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index d8b6a5dab190..29ced69d5c85 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -186,7 +186,7 @@  config MOUSE_PS2_FOCALTECH
 
 config MOUSE_PS2_VMMOUSE
 	bool "Virtual mouse (vmmouse)"
-	depends on MOUSE_PS2 && X86 && HYPERVISOR_GUEST
+	depends on MOUSE_PS2 && X86 && VMWARE_GUEST
 	help
 	  Say Y here if you are running under control of VMware hypervisor
 	  (ESXi, Workstation or Fusion). Also make sure that when you enable
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index fafa8b0d8099..d2bd8eff6eb6 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -363,7 +363,7 @@  config DS1682
 
 config VMWARE_BALLOON
 	tristate "VMware Balloon Driver"
-	depends on VMWARE_VMCI && X86 && HYPERVISOR_GUEST
+	depends on VMWARE_VMCI && X86 && VMWARE_GUEST
 	select MEMORY_BALLOON
 	help
 	  This is VMware physical memory management driver which acts
diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index 942f72d8151d..6bf30153270e 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -141,7 +141,7 @@  config PTP_1588_CLOCK_IDTCM
 
 config PTP_1588_CLOCK_VMW
 	tristate "VMware virtual PTP clock"
-	depends on ACPI && HYPERVISOR_GUEST && X86
+	depends on ACPI && VMWARE_GUEST && X86
 	depends on PTP_1588_CLOCK
 	help
 	  This driver adds support for using VMware virtual precision