| Message ID | 1438966019-19322-21-git-send-email-julien.grall@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 7 Aug 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_gfn is working with a Xen pfn (i.e 4KB). We may want to > rename pfn_gfn 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> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > --- > Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > Cc: Russell King <linux@arm.linux.org.uk> > > Stefano, I've dropped your reviewed-by given I've updated the doc and do > changes to avoid usage of XEN_PAGE_SHIFT > > Changes in v3: > - s/MFN/GFN/ base on the new naming > - Use virt_to_gfn to avoid use XEN_PAGE_SHIFT > - Drop Stefano's reviewed-by > - Add some docs in arch/arm/asm/xen/page.h > > Changes in v2 > - Add Stefano's reviewed-by > --- > arch/arm/include/asm/xen/page.h | 15 +++++++++++++-- > arch/arm/xen/enlighten.c | 6 +++--- > 2 files changed, 16 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h > index 98c9fc3..e3d94cf 100644 > --- a/arch/arm/include/asm/xen/page.h > +++ b/arch/arm/include/asm/xen/page.h > @@ -28,6 +28,17 @@ typedef struct xpaddr { > > #define INVALID_P2M_ENTRY (~0UL) > > +/* > + * The pseudo-physical frame (pfn) used in all the helpers is always based > + * on Xen page granularity (i.e 4KB). > + * > + * A Linux page may be split across multiple non-contiguous Xen page so we > + * have to keep track with frame based on 4KB page granularity. > + * > + * PV drivers should never make a direct usage of those helpers (particularly > + * pfn_to_gfn and gfn_to_pfn). > + */ > + > unsigned long __pfn_to_mfn(unsigned long pfn); > extern struct rb_root phys_to_mach; > > @@ -64,8 +75,8 @@ static inline unsigned long bfn_to_pfn(unsigned long bfn) > #define bfn_to_local_pfn(bfn) bfn_to_pfn(bfn) > > /* VIRT <-> GUEST conversion */ > -#define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) > -#define gfn_to_virt(m) (__va(gfn_to_pfn(m) << PAGE_SHIFT)) > +#define virt_to_gfn(v) (pfn_to_gfn(virt_to_phys(v) >> XEN_PAGE_SHIFT)) > +#define gfn_to_virt(m) (__va(gfn_to_pfn(m) << XEN_PAGE_SHIFT)) > > /* Only used in PV code. But ARM guests are always HVM. */ > 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 eeeab07..50b4769 100644 > --- a/arch/arm/xen/enlighten.c > +++ b/arch/arm/xen/enlighten.c > @@ -89,8 +89,8 @@ 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 = virt_to_gfn(vcpup); > + info.offset = xen_offset_in_page(vcpup); > > err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info); > BUG_ON(err); > @@ -213,7 +213,7 @@ 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 = virt_to_gfn(shared_info_page); > if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) > BUG(); > > -- > 2.1.4 >
diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index 98c9fc3..e3d94cf 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -28,6 +28,17 @@ typedef struct xpaddr { #define INVALID_P2M_ENTRY (~0UL) +/* + * The pseudo-physical frame (pfn) used in all the helpers is always based + * on Xen page granularity (i.e 4KB). + * + * A Linux page may be split across multiple non-contiguous Xen page so we + * have to keep track with frame based on 4KB page granularity. + * + * PV drivers should never make a direct usage of those helpers (particularly + * pfn_to_gfn and gfn_to_pfn). + */ + unsigned long __pfn_to_mfn(unsigned long pfn); extern struct rb_root phys_to_mach; @@ -64,8 +75,8 @@ static inline unsigned long bfn_to_pfn(unsigned long bfn) #define bfn_to_local_pfn(bfn) bfn_to_pfn(bfn) /* VIRT <-> GUEST conversion */ -#define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) -#define gfn_to_virt(m) (__va(gfn_to_pfn(m) << PAGE_SHIFT)) +#define virt_to_gfn(v) (pfn_to_gfn(virt_to_phys(v) >> XEN_PAGE_SHIFT)) +#define gfn_to_virt(m) (__va(gfn_to_pfn(m) << XEN_PAGE_SHIFT)) /* Only used in PV code. But ARM guests are always HVM. */ 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 eeeab07..50b4769 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -89,8 +89,8 @@ 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 = virt_to_gfn(vcpup); + info.offset = xen_offset_in_page(vcpup); err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info); BUG_ON(err); @@ -213,7 +213,7 @@ 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 = virt_to_gfn(shared_info_page); 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_gfn is working with a Xen pfn (i.e 4KB). We may want to rename pfn_gfn 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> Stefano, I've dropped your reviewed-by given I've updated the doc and do changes to avoid usage of XEN_PAGE_SHIFT Changes in v3: - s/MFN/GFN/ base on the new naming - Use virt_to_gfn to avoid use XEN_PAGE_SHIFT - Drop Stefano's reviewed-by - Add some docs in arch/arm/asm/xen/page.h Changes in v2 - Add Stefano's reviewed-by --- arch/arm/include/asm/xen/page.h | 15 +++++++++++++-- arch/arm/xen/enlighten.c | 6 +++--- 2 files changed, 16 insertions(+), 5 deletions(-)