Re: [Xen-devel] [RFC 23/23] arm/xen: Add support for 64KB page granularity
On Thu, 14 May 2015, Julien Grall wrote:
> The hypercall interface is always using 4KB page granularity. This is
> requiring to use xen page definition macro when we deal with hypercall.
>
> Note that pfn_to_mfn is working with a Xen pfn (i.e 4KB). We may want to
> rename pfn_mfn to make this explicit.
>
> We also allocate a 64KB page for the shared page even though only the
> first 4KB is used. I don't think this is really important for now as it
> helps to have the pointer 4KB aligned (XENMEM_add_to_physmap is taking a
> Xen PFN).
>
> Signed-off-by: Julien Grall
> Cc: Stefano Stabellini
> Cc: Russell King
>
> arch/arm/include/asm/xen/page.h | 12 ++--
> arch/arm/xen/enlighten.c| 6 +++---
> 2 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
> index 1bee8ca..ab6eb9a 100644
> --- a/arch/arm/include/asm/xen/page.h
> +++ b/arch/arm/include/asm/xen/page.h
> @@ -56,19 +56,19 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
>
> static inline xmaddr_t phys_to_machine(xpaddr_t phys)
> {
> - unsigned offset = phys.paddr & ~PAGE_MASK;
> - return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
> + unsigned offset = phys.paddr & ~XEN_PAGE_MASK;
> + return XMADDR(XEN_PFN_PHYS(pfn_to_mfn(XEN_PFN_DOWN(phys.paddr))) |
> offset);
> }
>
> static inline xpaddr_t machine_to_phys(xmaddr_t machine)
> {
> - unsigned offset = machine.maddr & ~PAGE_MASK;
> - return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
> + unsigned offset = machine.maddr & ~XEN_PAGE_MASK;
> + return XPADDR(XEN_PFN_PHYS(mfn_to_pfn(XEN_PFN_DOWN(machine.maddr))) |
> offset);
> }
> /* VIRT <-> MACHINE conversion */
> #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v
> -#define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
> -#define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
> +#define virt_to_mfn(v) (pfn_to_mfn(virt_to_phys(v) >>
> XEN_PAGE_SHIFT))
> +#define mfn_to_virt(m) (__va(mfn_to_pfn(m) << XEN_PAGE_SHIFT))
>
> static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
> {
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 224081c..dcfe251 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -93,8 +93,8 @@ static void xen_percpu_init(void)
> pr_info("Xen: initializing cpu%d\n", cpu);
> vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
>
> - info.mfn = __pa(vcpup) >> PAGE_SHIFT;
> - info.offset = offset_in_page(vcpup);
> + info.mfn = __pa(vcpup) >> XEN_PAGE_SHIFT;
> + info.offset = xen_offset_in_page(vcpup);
>
> err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
> BUG_ON(err);
> @@ -204,7 +204,7 @@ static int __init xen_guest_init(void)
> xatp.domid = DOMID_SELF;
> xatp.idx = 0;
> xatp.space = XENMAPSPACE_shared_info;
> - xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> + xatp.gpfn = __pa(shared_info_page) >> XEN_PAGE_SHIFT;
> if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> BUG();
What about xen_remap_domain_mfn_range? I guess we don't support that use
case on 64K guests? If so, I would appreaciate an assert and/or an error
message.
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Re: [Xen-devel] [RFC 23/23] arm/xen: Add support for 64KB page granularity
Hi,
On 23/06/15 15:19, Stefano Stabellini wrote:
>> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
>> index 224081c..dcfe251 100644
>> --- a/arch/arm/xen/enlighten.c
>> +++ b/arch/arm/xen/enlighten.c
>> @@ -93,8 +93,8 @@ static void xen_percpu_init(void)
>> pr_info("Xen: initializing cpu%d\n", cpu);
>> vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
>>
>> -info.mfn = __pa(vcpup) >> PAGE_SHIFT;
>> -info.offset = offset_in_page(vcpup);
>> +info.mfn = __pa(vcpup) >> XEN_PAGE_SHIFT;
>> +info.offset = xen_offset_in_page(vcpup);
>>
>> err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
>> BUG_ON(err);
>> @@ -204,7 +204,7 @@ static int __init xen_guest_init(void)
>> xatp.domid = DOMID_SELF;
>> xatp.idx = 0;
>> xatp.space = XENMAPSPACE_shared_info;
>> -xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
>> +xatp.gpfn = __pa(shared_info_page) >> XEN_PAGE_SHIFT;
>> if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
>> BUG();
>
> What about xen_remap_domain_mfn_range? I guess we don't support that use
> case on 64K guests? If so, I would appreaciate an assert and/or an error
> message.
The implementation of xen_remap_domain_mfn_range return -ENOSYS no
matter the page granularity.
This function is PV specific and has been added few months ago just for
a stub. See comment in the code:
"/* Not used by XENFEAT_auto_translated guests */"
Any logging/BUG_ON within this function is out of scope for this series.
And I don't think this will be really useful. Feel free to send a patch
for it.
Regards,
--
Julien Grall
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Re: [Xen-devel] [RFC 23/23] arm/xen: Add support for 64KB page granularity
On Tue, 23 Jun 2015, Julien Grall wrote:
> Hi,
>
> On 23/06/15 15:19, Stefano Stabellini wrote:
> >> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> >> index 224081c..dcfe251 100644
> >> --- a/arch/arm/xen/enlighten.c
> >> +++ b/arch/arm/xen/enlighten.c
> >> @@ -93,8 +93,8 @@ static void xen_percpu_init(void)
> >>pr_info("Xen: initializing cpu%d\n", cpu);
> >>vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
> >>
> >> - info.mfn = __pa(vcpup) >> PAGE_SHIFT;
> >> - info.offset = offset_in_page(vcpup);
> >> + info.mfn = __pa(vcpup) >> XEN_PAGE_SHIFT;
> >> + info.offset = xen_offset_in_page(vcpup);
> >>
> >>err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
> >>BUG_ON(err);
> >> @@ -204,7 +204,7 @@ static int __init xen_guest_init(void)
> >>xatp.domid = DOMID_SELF;
> >>xatp.idx = 0;
> >>xatp.space = XENMAPSPACE_shared_info;
> >> - xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> >> + xatp.gpfn = __pa(shared_info_page) >> XEN_PAGE_SHIFT;
> >>if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> >>BUG();
> >
> > What about xen_remap_domain_mfn_range? I guess we don't support that use
> > case on 64K guests? If so, I would appreaciate an assert and/or an error
> > message.
>
> The implementation of xen_remap_domain_mfn_range return -ENOSYS no
> matter the page granularity.
>
> This function is PV specific and has been added few months ago just for
> a stub. See comment in the code:
> "/* Not used by XENFEAT_auto_translated guests */"
>
> Any logging/BUG_ON within this function is out of scope for this series.
> And I don't think this will be really useful. Feel free to send a patch
> for it.
Yes, you are right, I was reading an older version of Linux that still
had xen_remap_domain_mfn_range properly implemented.
The new function is called xen_remap_domain_mfn_array which calls
xen_xlate_remap_gfn_array.
I'll rephrase my question then: What about xen_remap_domain_mfn_array? I
guess we don't support that use case on 64K guests? If so, I would
appreaciate an assert and/or an error message.
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Re: [Xen-devel] [RFC 23/23] arm/xen: Add support for 64KB page granularity
On 23/06/15 15:49, Stefano Stabellini wrote: > Yes, you are right, I was reading an older version of Linux that still > had xen_remap_domain_mfn_range properly implemented. > > The new function is called xen_remap_domain_mfn_array which calls > xen_xlate_remap_gfn_array. > > I'll rephrase my question then: What about xen_remap_domain_mfn_array? I > guess we don't support that use case on 64K guests? If so, I would > appreaciate an assert and/or an error message. See https://lkml.org/lkml/2015/5/14/563 -- Julien Grall ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [RFC 23/23] arm/xen: Add support for 64KB page granularity
On Tue, 23 Jun 2015, Julien Grall wrote: > On 23/06/15 15:49, Stefano Stabellini wrote: > > Yes, you are right, I was reading an older version of Linux that still > > had xen_remap_domain_mfn_range properly implemented. > > > > The new function is called xen_remap_domain_mfn_array which calls > > xen_xlate_remap_gfn_array. > > > > I'll rephrase my question then: What about xen_remap_domain_mfn_array? I > > guess we don't support that use case on 64K guests? If so, I would > > appreaciate an assert and/or an error message. > > See https://lkml.org/lkml/2015/5/14/563 Ah, that's fantastic! In that case: Reviewed-by: Stefano Stabellini ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
