diff mbox series

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

Message ID 20250220095349.1823593-1-Jiqian.Chen@amd.com (mailing list archive)
State New
Headers show
Series [v2,1/2] x86/hvm: make stdvga support optional | expand

Commit Message

Chen, Jiqian Feb. 20, 2025, 9:53 a.m. UTC 
From: Sergiy Kibrik <Sergiy_Kibrik@epam.com>

Introduce config option X86_STDVGA so that stdvga driver can be
disabled on systems that don't need it.

What's more, in function emulation_flags_ok, to check if toolstack
pass any emulation flag that disabled in building time.

Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
---
Hi all,
this is a rework for https://lore.kernel.org/xen-devel/20240912085709.858052-1-Sergiy_Kibrik@epam.com/T/#u.

v1->v2 changes:
* For emulation flags, added a new file "arch/x86/hvm/Kconfig.emu" to be a separate seletion,
  and moved definition of "config X86_STDVGA" into it.
* Added a new macro "#define DISABLED_EMU_MASK (!IS_ENABLED(CONFIG_X86_STDVGA) ? X86_EMU_VGA : 0)",
  and checked it in function emulation_flags_ok.
* Adjusted macro "has_vvga".

Best regards,
Jiqian Chen.
---
 xen/arch/x86/Kconfig              |  2 ++
 xen/arch/x86/domain.c             |  2 ++
 xen/arch/x86/hvm/Kconfig.emu      | 14 ++++++++++++++
 xen/arch/x86/hvm/Makefile         |  2 +-
 xen/arch/x86/include/asm/domain.h |  6 +++++-
 xen/arch/x86/include/asm/hvm/io.h |  4 ++++
 6 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 xen/arch/x86/hvm/Kconfig.emu

Comments

Chen, Jiqian Feb. 20, 2025, 10:12 a.m. UTC | #1 
Hi all,

On 2025/2/20 17:53, Jiqian Chen wrote:
> From: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
> 
> Introduce config option X86_STDVGA so that stdvga driver can be
> disabled on systems that don't need it.
> 
> What's more, in function emulation_flags_ok, to check if toolstack
> pass any emulation flag that disabled in building time.
> 
I am sorry.
After sending my series, I just found out that there are v3 for this work.
https://lore.kernel.org/xen-devel/7a0ee883-8542-4e17-adeb-9c1d83f58657@suse.com/
And it seems that the v3 has no other implementation-related comment, just waiting for x86 Maintainers' opinion.

> Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
> Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
> ---
> Hi all,
> this is a rework for https://lore.kernel.org/xen-devel/20240912085709.858052-1-Sergiy_Kibrik@epam.com/T/#u.
> 
> v1->v2 changes:
> * For emulation flags, added a new file "arch/x86/hvm/Kconfig.emu" to be a separate seletion,
>   and moved definition of "config X86_STDVGA" into it.
> * Added a new macro "#define DISABLED_EMU_MASK (!IS_ENABLED(CONFIG_X86_STDVGA) ? X86_EMU_VGA : 0)",
>   and checked it in function emulation_flags_ok.
> * Adjusted macro "has_vvga".
> 
> Best regards,
> Jiqian Chen.
> ---
>  xen/arch/x86/Kconfig              |  2 ++
>  xen/arch/x86/domain.c             |  2 ++
>  xen/arch/x86/hvm/Kconfig.emu      | 14 ++++++++++++++
>  xen/arch/x86/hvm/Makefile         |  2 +-
>  xen/arch/x86/include/asm/domain.h |  6 +++++-
>  xen/arch/x86/include/asm/hvm/io.h |  4 ++++
>  6 files changed, 28 insertions(+), 2 deletions(-)
>  create mode 100644 xen/arch/x86/hvm/Kconfig.emu
> 
> diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
> index 9cdd04721afa..e4fedf7e54d8 100644
> --- a/xen/arch/x86/Kconfig
> +++ b/xen/arch/x86/Kconfig
> @@ -123,6 +123,8 @@ config HVM
>  
>  	  If unsure, say Y.
>  
> +source "arch/x86/hvm/Kconfig.emu"
> +
>  config AMD_SVM
>  	bool "AMD-V" if EXPERT
>  	depends on HVM
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index 78a13e6812c9..289c91459470 100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -758,6 +758,8 @@ static bool emulation_flags_ok(const struct domain *d, uint32_t emflags)
>               (X86_EMU_ALL & ~(X86_EMU_VPCI | X86_EMU_USE_PIRQ)) &&
>               emflags != X86_EMU_LAPIC )
>              return false;
> +        if ( emflags & DISABLED_EMU_MASK )
> +            return false;
>      }
>      else if ( emflags != 0 && emflags != X86_EMU_PIT )
>      {
> diff --git a/xen/arch/x86/hvm/Kconfig.emu b/xen/arch/x86/hvm/Kconfig.emu
> new file mode 100644
> index 000000000000..aa60b6227036
> --- /dev/null
> +++ b/xen/arch/x86/hvm/Kconfig.emu
> @@ -0,0 +1,14 @@
> +menu "Emulated device support"
> +	visible if EXPERT
> +
> +config X86_STDVGA
> +	bool "Standard VGA card emulation support" if EXPERT
> +	default y
> +	depends on HVM
> +	help
> +	  Build stdvga driver that emulates standard VGA card with VESA BIOS
> +	  Extensions for HVM guests.
> +
> +	  If unsure, say Y.
> +
> +endmenu
> diff --git a/xen/arch/x86/hvm/Makefile b/xen/arch/x86/hvm/Makefile
> index 4c1fa5c6c2bf..4d1f8e00eb68 100644
> --- a/xen/arch/x86/hvm/Makefile
> +++ b/xen/arch/x86/hvm/Makefile
> @@ -22,7 +22,7 @@ obj-y += pmtimer.o
>  obj-y += quirks.o
>  obj-y += rtc.o
>  obj-y += save.o
> -obj-y += stdvga.o
> +obj-$(CONFIG_X86_STDVGA) += stdvga.o
>  obj-y += vioapic.o
>  obj-y += vlapic.o
>  obj-y += vm_event.o
> diff --git a/xen/arch/x86/include/asm/domain.h b/xen/arch/x86/include/asm/domain.h
> index b79d6badd71c..68be23bf3bf4 100644
> --- a/xen/arch/x86/include/asm/domain.h
> +++ b/xen/arch/x86/include/asm/domain.h
> @@ -494,13 +494,17 @@ struct arch_domain
>                                   X86_EMU_PIT | X86_EMU_USE_PIRQ |       \
>                                   X86_EMU_VPCI)
>  
> +#define DISABLED_EMU_MASK \
> +    (!IS_ENABLED(CONFIG_X86_STDVGA) ? X86_EMU_VGA : 0)
> +
>  #define has_vlapic(d)      (!!((d)->arch.emulation_flags & X86_EMU_LAPIC))
>  #define has_vhpet(d)       (!!((d)->arch.emulation_flags & X86_EMU_HPET))
>  #define has_vpm(d)         (!!((d)->arch.emulation_flags & X86_EMU_PM))
>  #define has_vrtc(d)        (!!((d)->arch.emulation_flags & X86_EMU_RTC))
>  #define has_vioapic(d)     (!!((d)->arch.emulation_flags & X86_EMU_IOAPIC))
>  #define has_vpic(d)        (!!((d)->arch.emulation_flags & X86_EMU_PIC))
> -#define has_vvga(d)        (!!((d)->arch.emulation_flags & X86_EMU_VGA))
> +#define has_vvga(d)        (IS_ENABLED(CONFIG_X86_STDVGA) && \
> +                            !!((d)->arch.emulation_flags & X86_EMU_VGA))
>  #define has_viommu(d)      (!!((d)->arch.emulation_flags & X86_EMU_IOMMU))
>  #define has_vpit(d)        (!!((d)->arch.emulation_flags & X86_EMU_PIT))
>  #define has_pirq(d)        (!!((d)->arch.emulation_flags & X86_EMU_USE_PIRQ))
> diff --git a/xen/arch/x86/include/asm/hvm/io.h b/xen/arch/x86/include/asm/hvm/io.h
> index f2b8431facb0..32a2490fbcb2 100644
> --- a/xen/arch/x86/include/asm/hvm/io.h
> +++ b/xen/arch/x86/include/asm/hvm/io.h
> @@ -108,7 +108,11 @@ struct vpci_arch_msix_entry {
>      int pirq;
>  };
>  
> +#ifdef CONFIG_X86_STDVGA
>  void stdvga_init(struct domain *d);
> +#else
> +static inline void stdvga_init(struct domain *d) {}
> +#endif
>  
>  extern void hvm_dpci_msi_eoi(struct domain *d, int vector);
>
Jan Beulich Feb. 20, 2025, 12:49 p.m. UTC | #2 
On 20.02.2025 11:12, Chen, Jiqian wrote:
> On 2025/2/20 17:53, Jiqian Chen wrote:
>> From: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
>>
>> Introduce config option X86_STDVGA so that stdvga driver can be
>> disabled on systems that don't need it.
>>
>> What's more, in function emulation_flags_ok, to check if toolstack
>> pass any emulation flag that disabled in building time.
>>
> I am sorry.
> After sending my series, I just found out that there are v3 for this work.
> https://lore.kernel.org/xen-devel/7a0ee883-8542-4e17-adeb-9c1d83f58657@suse.com/
> And it seems that the v3 has no other implementation-related comment, just waiting for x86 Maintainers' opinion.

I certainly voiced my take, in reply to the v3 cover letter.

Jan
Denis Mukhin Feb. 21, 2025, 8:54 p.m. UTC | #3 
On Thursday, February 20th, 2025 at 1:53 AM, Jiqian Chen <Jiqian.Chen@amd.com> wrote:

>
>
> From: Sergiy Kibrik Sergiy_Kibrik@epam.com
>
>
> Introduce config option X86_STDVGA so that stdvga driver can be
> disabled on systems that don't need it.
>
> What's more, in function emulation_flags_ok, to check if toolstack
> pass any emulation flag that disabled in building time.
>
> Signed-off-by: Sergiy Kibrik Sergiy_Kibrik@epam.com
>
> Signed-off-by: Jiqian Chen Jiqian.Chen@amd.com
>
> ---
> Hi all,
> this is a rework for https://lore.kernel.org/xen-devel/20240912085709.858052-1-Sergiy_Kibrik@epam.com/T/#u.
>
> v1->v2 changes:
>
> * For emulation flags, added a new file "arch/x86/hvm/Kconfig.emu" to be a separate seletion,
> and moved definition of "config X86_STDVGA" into it.
> * Added a new macro "#define DISABLED_EMU_MASK (!IS_ENABLED(CONFIG_X86_STDVGA) ? X86_EMU_VGA : 0)",
> and checked it in function emulation_flags_ok.
> * Adjusted macro "has_vvga".
>
> Best regards,
> Jiqian Chen.
> ---
> xen/arch/x86/Kconfig | 2 ++
> xen/arch/x86/domain.c | 2 ++
> xen/arch/x86/hvm/Kconfig.emu | 14 ++++++++++++++
> xen/arch/x86/hvm/Makefile | 2 +-
> xen/arch/x86/include/asm/domain.h | 6 +++++-
> xen/arch/x86/include/asm/hvm/io.h | 4 ++++
> 6 files changed, 28 insertions(+), 2 deletions(-)
> create mode 100644 xen/arch/x86/hvm/Kconfig.emu
>
> diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
> index 9cdd04721afa..e4fedf7e54d8 100644
> --- a/xen/arch/x86/Kconfig
> +++ b/xen/arch/x86/Kconfig
> @@ -123,6 +123,8 @@ config HVM
>
> If unsure, say Y.
>
> +source "arch/x86/hvm/Kconfig.emu"

JFYI, there's this patch:
  https://lore.kernel.org/xen-devel/20250207220302.4190210-1-dmukhin@ford.com/

I think having one Kconfig under arch/x86/hvm is enough.
Thoughts?

> +
> config AMD_SVM
> bool "AMD-V" if EXPERT
> depends on HVM
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index 78a13e6812c9..289c91459470 100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -758,6 +758,8 @@ static bool emulation_flags_ok(const struct domain *d, uint32_t emflags)
> (X86_EMU_ALL & ~(X86_EMU_VPCI | X86_EMU_USE_PIRQ)) &&
> emflags != X86_EMU_LAPIC )
> return false;
> + if ( emflags & DISABLED_EMU_MASK )
> + return false;
> }
> else if ( emflags != 0 && emflags != X86_EMU_PIT )
> {
> diff --git a/xen/arch/x86/hvm/Kconfig.emu b/xen/arch/x86/hvm/Kconfig.emu
> new file mode 100644
> index 000000000000..aa60b6227036
> --- /dev/null
> +++ b/xen/arch/x86/hvm/Kconfig.emu
> @@ -0,0 +1,14 @@
> +menu "Emulated device support"
> + visible if EXPERT
> +
> +config X86_STDVGA
> + bool "Standard VGA card emulation support" if EXPERT
> + default y
> + depends on HVM
> + help
> + Build stdvga driver that emulates standard VGA card with VESA BIOS
> + Extensions for HVM guests.
> +
> + If unsure, say Y.
> +
> +endmenu
> diff --git a/xen/arch/x86/hvm/Makefile b/xen/arch/x86/hvm/Makefile
> index 4c1fa5c6c2bf..4d1f8e00eb68 100644
> --- a/xen/arch/x86/hvm/Makefile
> +++ b/xen/arch/x86/hvm/Makefile
> @@ -22,7 +22,7 @@ obj-y += pmtimer.o
> obj-y += quirks.o
> obj-y += rtc.o
> obj-y += save.o
> -obj-y += stdvga.o
> +obj-$(CONFIG_X86_STDVGA) += stdvga.o
> obj-y += vioapic.o
> obj-y += vlapic.o
> obj-y += vm_event.o
> diff --git a/xen/arch/x86/include/asm/domain.h b/xen/arch/x86/include/asm/domain.h
> index b79d6badd71c..68be23bf3bf4 100644
> --- a/xen/arch/x86/include/asm/domain.h
> +++ b/xen/arch/x86/include/asm/domain.h
> @@ -494,13 +494,17 @@ struct arch_domain
> X86_EMU_PIT | X86_EMU_USE_PIRQ | \
> X86_EMU_VPCI)
>
> +#define DISABLED_EMU_MASK \
> + (!IS_ENABLED(CONFIG_X86_STDVGA) ? X86_EMU_VGA : 0)
> +
> #define has_vlapic(d) (!!((d)->arch.emulation_flags & X86_EMU_LAPIC))
>
> #define has_vhpet(d) (!!((d)->arch.emulation_flags & X86_EMU_HPET))
>
> #define has_vpm(d) (!!((d)->arch.emulation_flags & X86_EMU_PM))
>
> #define has_vrtc(d) (!!((d)->arch.emulation_flags & X86_EMU_RTC))
>
> #define has_vioapic(d) (!!((d)->arch.emulation_flags & X86_EMU_IOAPIC))
>
> #define has_vpic(d) (!!((d)->arch.emulation_flags & X86_EMU_PIC))
>
> -#define has_vvga(d) (!!((d)->arch.emulation_flags & X86_EMU_VGA))
>
> +#define has_vvga(d) (IS_ENABLED(CONFIG_X86_STDVGA) && \
> + !!((d)->arch.emulation_flags & X86_EMU_VGA))
>
> #define has_viommu(d) (!!((d)->arch.emulation_flags & X86_EMU_IOMMU))
>
> #define has_vpit(d) (!!((d)->arch.emulation_flags & X86_EMU_PIT))
>
> #define has_pirq(d) (!!((d)->arch.emulation_flags & X86_EMU_USE_PIRQ))
>
> diff --git a/xen/arch/x86/include/asm/hvm/io.h b/xen/arch/x86/include/asm/hvm/io.h
> index f2b8431facb0..32a2490fbcb2 100644
> --- a/xen/arch/x86/include/asm/hvm/io.h
> +++ b/xen/arch/x86/include/asm/hvm/io.h
> @@ -108,7 +108,11 @@ struct vpci_arch_msix_entry {
> int pirq;
> };
>
> +#ifdef CONFIG_X86_STDVGA
> void stdvga_init(struct domain *d);
> +#else
> +static inline void stdvga_init(struct domain *d) {}
> +#endif
>
> extern void hvm_dpci_msi_eoi(struct domain *d, int vector);
>
> --
> 2.34.1
diff mbox series

Patch

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 9cdd04721afa..e4fedf7e54d8 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -123,6 +123,8 @@  config HVM
 
 	  If unsure, say Y.
 
+source "arch/x86/hvm/Kconfig.emu"
+
 config AMD_SVM
 	bool "AMD-V" if EXPERT
 	depends on HVM
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 78a13e6812c9..289c91459470 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -758,6 +758,8 @@  static bool emulation_flags_ok(const struct domain *d, uint32_t emflags)
              (X86_EMU_ALL & ~(X86_EMU_VPCI | X86_EMU_USE_PIRQ)) &&
              emflags != X86_EMU_LAPIC )
             return false;
+        if ( emflags & DISABLED_EMU_MASK )
+            return false;
     }
     else if ( emflags != 0 && emflags != X86_EMU_PIT )
     {
diff --git a/xen/arch/x86/hvm/Kconfig.emu b/xen/arch/x86/hvm/Kconfig.emu
new file mode 100644
index 000000000000..aa60b6227036
--- /dev/null
+++ b/xen/arch/x86/hvm/Kconfig.emu
@@ -0,0 +1,14 @@ 
+menu "Emulated device support"
+	visible if EXPERT
+
+config X86_STDVGA
+	bool "Standard VGA card emulation support" if EXPERT
+	default y
+	depends on HVM
+	help
+	  Build stdvga driver that emulates standard VGA card with VESA BIOS
+	  Extensions for HVM guests.
+
+	  If unsure, say Y.
+
+endmenu
diff --git a/xen/arch/x86/hvm/Makefile b/xen/arch/x86/hvm/Makefile
index 4c1fa5c6c2bf..4d1f8e00eb68 100644
--- a/xen/arch/x86/hvm/Makefile
+++ b/xen/arch/x86/hvm/Makefile
@@ -22,7 +22,7 @@  obj-y += pmtimer.o
 obj-y += quirks.o
 obj-y += rtc.o
 obj-y += save.o
-obj-y += stdvga.o
+obj-$(CONFIG_X86_STDVGA) += stdvga.o
 obj-y += vioapic.o
 obj-y += vlapic.o
 obj-y += vm_event.o
diff --git a/xen/arch/x86/include/asm/domain.h b/xen/arch/x86/include/asm/domain.h
index b79d6badd71c..68be23bf3bf4 100644
--- a/xen/arch/x86/include/asm/domain.h
+++ b/xen/arch/x86/include/asm/domain.h
@@ -494,13 +494,17 @@  struct arch_domain
                                  X86_EMU_PIT | X86_EMU_USE_PIRQ |       \
                                  X86_EMU_VPCI)
 
+#define DISABLED_EMU_MASK \
+    (!IS_ENABLED(CONFIG_X86_STDVGA) ? X86_EMU_VGA : 0)
+
 #define has_vlapic(d)      (!!((d)->arch.emulation_flags & X86_EMU_LAPIC))
 #define has_vhpet(d)       (!!((d)->arch.emulation_flags & X86_EMU_HPET))
 #define has_vpm(d)         (!!((d)->arch.emulation_flags & X86_EMU_PM))
 #define has_vrtc(d)        (!!((d)->arch.emulation_flags & X86_EMU_RTC))
 #define has_vioapic(d)     (!!((d)->arch.emulation_flags & X86_EMU_IOAPIC))
 #define has_vpic(d)        (!!((d)->arch.emulation_flags & X86_EMU_PIC))
-#define has_vvga(d)        (!!((d)->arch.emulation_flags & X86_EMU_VGA))
+#define has_vvga(d)        (IS_ENABLED(CONFIG_X86_STDVGA) && \
+                            !!((d)->arch.emulation_flags & X86_EMU_VGA))
 #define has_viommu(d)      (!!((d)->arch.emulation_flags & X86_EMU_IOMMU))
 #define has_vpit(d)        (!!((d)->arch.emulation_flags & X86_EMU_PIT))
 #define has_pirq(d)        (!!((d)->arch.emulation_flags & X86_EMU_USE_PIRQ))
diff --git a/xen/arch/x86/include/asm/hvm/io.h b/xen/arch/x86/include/asm/hvm/io.h
index f2b8431facb0..32a2490fbcb2 100644
--- a/xen/arch/x86/include/asm/hvm/io.h
+++ b/xen/arch/x86/include/asm/hvm/io.h
@@ -108,7 +108,11 @@  struct vpci_arch_msix_entry {
     int pirq;
 };
 
+#ifdef CONFIG_X86_STDVGA
 void stdvga_init(struct domain *d);
+#else
+static inline void stdvga_init(struct domain *d) {}
+#endif
 
 extern void hvm_dpci_msi_eoi(struct domain *d, int vector);