diff mbox

[RFC,v4,1/7] xen/pvh: Split CONFIG_XEN_PVH into CONFIG_PVH and CONFIG_XEN_PVH

Message ID 1519842483-8887-2-git-send-email-maran.wilson@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

Maran Wilson Feb. 28, 2018, 6:27 p.m. UTC
In order to pave the way for hypervisors other then Xen to use the PVH
entry point for VMs, we need to factor the PVH entry code into Xen specific
and hypervisor agnostic components. The first step in doing that, is to
create a new config option for PVH entry that can be enabled
independently from CONFIG_XEN.

Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
---
 arch/x86/Kconfig          | 8 ++++++++
 arch/x86/kernel/head_64.S | 4 ++--
 arch/x86/xen/Kconfig      | 3 ++-
 3 files changed, 12 insertions(+), 3 deletions(-)

Comments

Konrad Rzeszutek Wilk Feb. 28, 2018, 9:07 p.m. UTC | #1
On Wed, Feb 28, 2018 at 10:27:57AM -0800, Maran Wilson wrote:
> In order to pave the way for hypervisors other then Xen to use the PVH
> entry point for VMs, we need to factor the PVH entry code into Xen specific
> and hypervisor agnostic components. The first step in doing that, is to
> create a new config option for PVH entry that can be enabled
> independently from CONFIG_XEN.
> 
> Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
> ---
>  arch/x86/Kconfig          | 8 ++++++++
>  arch/x86/kernel/head_64.S | 4 ++--
>  arch/x86/xen/Kconfig      | 3 ++-
>  3 files changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index eb7f43f23521..fa7cd0305125 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -791,6 +791,14 @@ config KVM_GUEST
>  	  underlying device model, the host provides the guest with
>  	  timing infrastructure such as time of day, and system time
>  
> +config PVH
> +	bool "Support for running PVH guests"
> +	depends on KVM_GUEST || XEN
> +	def_bool n
> +	---help---
> +	  This option enables the PVH entry point for guest virtual machines
> +	  as specified in the x86/HVM direct boot ABI.
> +
>  config KVM_DEBUG_FS
>  	bool "Enable debug information for KVM Guests in debugfs"
>  	depends on KVM_GUEST && DEBUG_FS
> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> index 0f545b3cf926..fc9f678c6413 100644
> --- a/arch/x86/kernel/head_64.S
> +++ b/arch/x86/kernel/head_64.S
> @@ -41,7 +41,7 @@
>  
>  #define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
>  
> -#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
> +#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
>  PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
>  PGD_START_KERNEL = pgd_index(__START_KERNEL_map)
>  #endif
> @@ -387,7 +387,7 @@ NEXT_PAGE(early_dynamic_pgts)
>  
>  	.data
>  
> -#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
> +#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
>  NEXT_PGD_PAGE(init_top_pgt)
>  	.quad   level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
>  	.org    init_top_pgt + PGD_PAGE_OFFSET*8, 0
> diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
> index f605825a04ab..021c8591c3c0 100644
> --- a/arch/x86/xen/Kconfig
> +++ b/arch/x86/xen/Kconfig
> @@ -77,8 +77,9 @@ config XEN_DEBUG_FS
>  	  Enabling this option may incur a significant performance overhead.
>  
>  config XEN_PVH
> -	bool "Support for running as a PVH guest"
> +	bool "Support for running as a Xen PVH guest"
>  	depends on XEN && XEN_PVHVM && ACPI
>  	# Pre-built page tables are not ready to handle 5-level paging.
>  	depends on !X86_5LEVEL

Not specific to this patch, but why is this there? PVH is not using PV so
there should be no problems with 5 level paging.

Juergen, thoughts?

> +	select PVH
>  	def_bool n
> -- 
> 2.16.1
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
Jürgen Groß March 1, 2018, 5:43 a.m. UTC | #2
On 28/02/18 22:07, Konrad Rzeszutek Wilk wrote:
> On Wed, Feb 28, 2018 at 10:27:57AM -0800, Maran Wilson wrote:
>> In order to pave the way for hypervisors other then Xen to use the PVH
>> entry point for VMs, we need to factor the PVH entry code into Xen specific
>> and hypervisor agnostic components. The first step in doing that, is to
>> create a new config option for PVH entry that can be enabled
>> independently from CONFIG_XEN.
>>
>> Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
>> ---
>>  arch/x86/Kconfig          | 8 ++++++++
>>  arch/x86/kernel/head_64.S | 4 ++--
>>  arch/x86/xen/Kconfig      | 3 ++-
>>  3 files changed, 12 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index eb7f43f23521..fa7cd0305125 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -791,6 +791,14 @@ config KVM_GUEST
>>  	  underlying device model, the host provides the guest with
>>  	  timing infrastructure such as time of day, and system time
>>  
>> +config PVH
>> +	bool "Support for running PVH guests"
>> +	depends on KVM_GUEST || XEN
>> +	def_bool n
>> +	---help---
>> +	  This option enables the PVH entry point for guest virtual machines
>> +	  as specified in the x86/HVM direct boot ABI.
>> +
>>  config KVM_DEBUG_FS
>>  	bool "Enable debug information for KVM Guests in debugfs"
>>  	depends on KVM_GUEST && DEBUG_FS
>> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
>> index 0f545b3cf926..fc9f678c6413 100644
>> --- a/arch/x86/kernel/head_64.S
>> +++ b/arch/x86/kernel/head_64.S
>> @@ -41,7 +41,7 @@
>>  
>>  #define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
>>  
>> -#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
>> +#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
>>  PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
>>  PGD_START_KERNEL = pgd_index(__START_KERNEL_map)
>>  #endif
>> @@ -387,7 +387,7 @@ NEXT_PAGE(early_dynamic_pgts)
>>  
>>  	.data
>>  
>> -#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
>> +#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
>>  NEXT_PGD_PAGE(init_top_pgt)
>>  	.quad   level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
>>  	.org    init_top_pgt + PGD_PAGE_OFFSET*8, 0
>> diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
>> index f605825a04ab..021c8591c3c0 100644
>> --- a/arch/x86/xen/Kconfig
>> +++ b/arch/x86/xen/Kconfig
>> @@ -77,8 +77,9 @@ config XEN_DEBUG_FS
>>  	  Enabling this option may incur a significant performance overhead.
>>  
>>  config XEN_PVH
>> -	bool "Support for running as a PVH guest"
>> +	bool "Support for running as a Xen PVH guest"
>>  	depends on XEN && XEN_PVHVM && ACPI
>>  	# Pre-built page tables are not ready to handle 5-level paging.
>>  	depends on !X86_5LEVEL
> 
> Not specific to this patch, but why is this there? PVH is not using PV so
> there should be no problems with 5 level paging.
> 
> Juergen, thoughts?

This dependency will be removed with Kyrill's series enabling to boot
the same kernel with either 5- or 4-level paging.

Adding 5-level paging support to the PVH boot path could be done later.
OTOH the same could be achieved by using grub2 to boot in PVH mode (with
my grub2 PVH series) as this variant is using the common Linux boot
entry, not the PVH specific one.


Juergen
Jürgen Groß March 1, 2018, 7:19 a.m. UTC | #3
On 28/02/18 19:27, Maran Wilson wrote:
> In order to pave the way for hypervisors other then Xen to use the PVH
> entry point for VMs, we need to factor the PVH entry code into Xen specific
> and hypervisor agnostic components. The first step in doing that, is to
> create a new config option for PVH entry that can be enabled
> independently from CONFIG_XEN.
> 
> Signed-off-by: Maran Wilson <maran.wilson@oracle.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen
Boris Ostrovsky March 1, 2018, 3:02 p.m. UTC | #4
On 02/28/2018 01:27 PM, Maran Wilson wrote:
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index eb7f43f23521..fa7cd0305125 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -791,6 +791,14 @@ config KVM_GUEST
>  	  underlying device model, the host provides the guest with
>  	  timing infrastructure such as time of day, and system time
>  
> +config PVH
> +	bool "Support for running PVH guests"
> +	depends on KVM_GUEST || XEN


Not sure about XEN part. PVH is selected by XEN_PVH for Xen.

What about introducing KVM_GUEST_PVH that will select PVH and then drop
dependency here?


-boris

> +	def_bool n
> +	---help---
> +	  This option enables the PVH entry point for guest virtual machines
> +	  as specified in the x86/HVM direct boot ABI.
> +
>  


> diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
> index f605825a04ab..021c8591c3c0 100644
> --- a/arch/x86/xen/Kconfig
> +++ b/arch/x86/xen/Kconfig
> @@ -77,8 +77,9 @@ config XEN_DEBUG_FS
>  	  Enabling this option may incur a significant performance overhead.
>  
>  config XEN_PVH
> -	bool "Support for running as a PVH guest"
> +	bool "Support for running as a Xen PVH guest"
>  	depends on XEN && XEN_PVHVM && ACPI
>  	# Pre-built page tables are not ready to handle 5-level paging.
>  	depends on !X86_5LEVEL
> +	select PVH
>  	def_bool n
Paolo Bonzini March 1, 2018, 3:17 p.m. UTC | #5
On 01/03/2018 16:02, Boris Ostrovsky wrote:
> On 02/28/2018 01:27 PM, Maran Wilson wrote:
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index eb7f43f23521..fa7cd0305125 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -791,6 +791,14 @@ config KVM_GUEST
>>  	  underlying device model, the host provides the guest with
>>  	  timing infrastructure such as time of day, and system time
>>  
>> +config PVH
>> +	bool "Support for running PVH guests"
>> +	depends on KVM_GUEST || XEN
> 
> 
> Not sure about XEN part. PVH is selected by XEN_PVH for Xen.
> 
> What about introducing KVM_GUEST_PVH that will select PVH and then drop
> dependency here?

That is, "config KVM_GUEST_PVH" "depends on KVM_GUEST" "select PVH".
Sounds good to me.

Paolo

> 
> -boris
> 
>> +	def_bool n
>> +	---help---
>> +	  This option enables the PVH entry point for guest virtual machines
>> +	  as specified in the x86/HVM direct boot ABI.
>> +
>>  
> 
> 
>> diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
>> index f605825a04ab..021c8591c3c0 100644
>> --- a/arch/x86/xen/Kconfig
>> +++ b/arch/x86/xen/Kconfig
>> @@ -77,8 +77,9 @@ config XEN_DEBUG_FS
>>  	  Enabling this option may incur a significant performance overhead.
>>  
>>  config XEN_PVH
>> -	bool "Support for running as a PVH guest"
>> +	bool "Support for running as a Xen PVH guest"
>>  	depends on XEN && XEN_PVHVM && ACPI
>>  	# Pre-built page tables are not ready to handle 5-level paging.
>>  	depends on !X86_5LEVEL
>> +	select PVH
>>  	def_bool n
>
Maran Wilson March 1, 2018, 5:24 p.m. UTC | #6
On 3/1/2018 7:17 AM, Paolo Bonzini wrote:
> On 01/03/2018 16:02, Boris Ostrovsky wrote:
>> On 02/28/2018 01:27 PM, Maran Wilson wrote:
>>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>>> index eb7f43f23521..fa7cd0305125 100644
>>> --- a/arch/x86/Kconfig
>>> +++ b/arch/x86/Kconfig
>>> @@ -791,6 +791,14 @@ config KVM_GUEST
>>>   	  underlying device model, the host provides the guest with
>>>   	  timing infrastructure such as time of day, and system time
>>>   
>>> +config PVH
>>> +	bool "Support for running PVH guests"
>>> +	depends on KVM_GUEST || XEN
>>
>> Not sure about XEN part. PVH is selected by XEN_PVH for Xen.
>>
>> What about introducing KVM_GUEST_PVH that will select PVH and then drop
>> dependency here?
> That is, "config KVM_GUEST_PVH" "depends on KVM_GUEST" "select PVH".
> Sounds good to me.

OK, will do.

Thanks,
-Maran

> Paolo
>
>> -boris
>>
>>> +	def_bool n
>>> +	---help---
>>> +	  This option enables the PVH entry point for guest virtual machines
>>> +	  as specified in the x86/HVM direct boot ABI.
>>> +
>>>   
>>
>>> diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
>>> index f605825a04ab..021c8591c3c0 100644
>>> --- a/arch/x86/xen/Kconfig
>>> +++ b/arch/x86/xen/Kconfig
>>> @@ -77,8 +77,9 @@ config XEN_DEBUG_FS
>>>   	  Enabling this option may incur a significant performance overhead.
>>>   
>>>   config XEN_PVH
>>> -	bool "Support for running as a PVH guest"
>>> +	bool "Support for running as a Xen PVH guest"
>>>   	depends on XEN && XEN_PVHVM && ACPI
>>>   	# Pre-built page tables are not ready to handle 5-level paging.
>>>   	depends on !X86_5LEVEL
>>> +	select PVH
>>>   	def_bool n
diff mbox

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index eb7f43f23521..fa7cd0305125 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -791,6 +791,14 @@  config KVM_GUEST
 	  underlying device model, the host provides the guest with
 	  timing infrastructure such as time of day, and system time
 
+config PVH
+	bool "Support for running PVH guests"
+	depends on KVM_GUEST || XEN
+	def_bool n
+	---help---
+	  This option enables the PVH entry point for guest virtual machines
+	  as specified in the x86/HVM direct boot ABI.
+
 config KVM_DEBUG_FS
 	bool "Enable debug information for KVM Guests in debugfs"
 	depends on KVM_GUEST && DEBUG_FS
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 0f545b3cf926..fc9f678c6413 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -41,7 +41,7 @@ 
 
 #define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
 
-#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
+#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
 PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
 PGD_START_KERNEL = pgd_index(__START_KERNEL_map)
 #endif
@@ -387,7 +387,7 @@  NEXT_PAGE(early_dynamic_pgts)
 
 	.data
 
-#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
+#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
 NEXT_PGD_PAGE(init_top_pgt)
 	.quad   level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
 	.org    init_top_pgt + PGD_PAGE_OFFSET*8, 0
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index f605825a04ab..021c8591c3c0 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -77,8 +77,9 @@  config XEN_DEBUG_FS
 	  Enabling this option may incur a significant performance overhead.
 
 config XEN_PVH
-	bool "Support for running as a PVH guest"
+	bool "Support for running as a Xen PVH guest"
 	depends on XEN && XEN_PVHVM && ACPI
 	# Pre-built page tables are not ready to handle 5-level paging.
 	depends on !X86_5LEVEL
+	select PVH
 	def_bool n