| Message ID | 1431622863-28575-24-git-send-email-julien.grall@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <julien.grall@citrix.com> > Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > Cc: Russell King <linux@arm.linux.org.uk> > > 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.
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,
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.
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
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 <stefano.stabellini@eu.citrix.com>
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();
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 <julien.grall@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Russell King <linux@arm.linux.org.uk> --- arch/arm/include/asm/xen/page.h | 12 ++++++------ arch/arm/xen/enlighten.c | 6 +++--- 2 files changed, 9 insertions(+), 9 deletions(-)