| Message ID | 20170912003726.368-15-konrad.wilk@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
>>> On 12.09.17 at 02:37, <konrad@kernel.org> wrote: > With this change we can use _do_page_walk() to implement > arch_livepatch_lookup_mfn() which can be used to find out > vmap virtual addresses (as under x86 virt_to_mfn won't work > for vmap, but it does for arm!). How about using domain_page_map_to_mfn() instead? Jan
Hi Konrad, On 12/09/17 01:37, Konrad Rzeszutek Wilk wrote: > With this change we can use _do_page_walk() to implement > arch_livepatch_lookup_mfn() which can be used to find out > vmap virtual addresses (as under x86 virt_to_mfn won't work > for vmap, but it does for arm!). The reason is on ARM, virt_to_mfn is taking advantage of the hardware to perform the translation. I am wondering if on x86 you could use vmap_to_mfn. Cheers, > > Signed-off-by: Blaise Boscaccy <blaise.boscaccy@oracle.com> > Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > xen/arch/arm/livepatch.c | 7 ++++--- > xen/arch/x86/livepatch.c | 10 ++++++++++ > xen/arch/x86/x86_64/mm.c | 33 ++++++++++++++++++++++++--------- > xen/include/asm-x86/mm.h | 1 + > xen/include/xen/livepatch.h | 3 +++ > 5 files changed, 42 insertions(+), 12 deletions(-) > > diff --git a/xen/arch/arm/livepatch.c b/xen/arch/arm/livepatch.c > index e1d5d58f97..1771b3c558 100644 > --- a/xen/arch/arm/livepatch.c > +++ b/xen/arch/arm/livepatch.c > @@ -13,9 +13,10 @@ > #include <asm/livepatch.h> > #include <asm/mm.h> > > -/* Override macros from asm/page.h to make them work with mfn_t */ > -#undef virt_to_mfn > -#define virt_to_mfn(va) _mfn(__virt_to_mfn(va)) > +mfn_t arch_livepatch_lookup_mfn(unsigned long addr) > +{ > + return _mfn(__virt_to_mfn(addr)); > +} > > void arch_livepatch_revive(void) > { > diff --git a/xen/arch/x86/livepatch.c b/xen/arch/x86/livepatch.c > index 12287d445f..667573c6de 100644 > --- a/xen/arch/x86/livepatch.c > +++ b/xen/arch/x86/livepatch.c > @@ -14,6 +14,16 @@ > #include <asm/nmi.h> > #include <asm/livepatch.h> > > +mfn_t arch_livepatch_lookup_mfn(unsigned long addr) > +{ > + unsigned long cr3 = read_cr3() >> PAGE_SHIFT; > + > + if ( !mfn_valid(_mfn(cr3)) ) > + return INVALID_MFN; > + > + return _do_page_walk(cr3, addr); > +} > + > void arch_livepatch_revive(void) > { > /* Nothing to do. */ > diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c > index 11746730b4..f8a963bbba 100644 > --- a/xen/arch/x86/x86_64/mm.c > +++ b/xen/arch/x86/x86_64/mm.c > @@ -44,29 +44,28 @@ unsigned int __read_mostly m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START; > > l2_pgentry_t *compat_idle_pg_table_l2; > > -void *do_page_walk(struct vcpu *v, unsigned long addr) > +mfn_t _do_page_walk(unsigned long mfn, unsigned long addr) > { > - unsigned long mfn = pagetable_get_pfn(v->arch.guest_table); > l4_pgentry_t l4e, *l4t; > l3_pgentry_t l3e, *l3t; > l2_pgentry_t l2e, *l2t; > l1_pgentry_t l1e, *l1t; > > - if ( !is_pv_vcpu(v) || !is_canonical_address(addr) ) > - return NULL; > + if ( !is_canonical_address(addr) ) > + return INVALID_MFN; > > l4t = map_domain_page(_mfn(mfn)); > l4e = l4t[l4_table_offset(addr)]; > unmap_domain_page(l4t); > if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) ) > - return NULL; > + return INVALID_MFN; > > l3t = map_l3t_from_l4e(l4e); > l3e = l3t[l3_table_offset(addr)]; > unmap_domain_page(l3t); > mfn = l3e_get_pfn(l3e); > if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) || !mfn_valid(_mfn(mfn)) ) > - return NULL; > + return INVALID_MFN; > if ( (l3e_get_flags(l3e) & _PAGE_PSE) ) > { > mfn += PFN_DOWN(addr & ((1UL << L3_PAGETABLE_SHIFT) - 1)); > @@ -78,7 +77,7 @@ void *do_page_walk(struct vcpu *v, unsigned long addr) > unmap_domain_page(l2t); > mfn = l2e_get_pfn(l2e); > if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) || !mfn_valid(_mfn(mfn)) ) > - return NULL; > + return INVALID_MFN; > if ( (l2e_get_flags(l2e) & _PAGE_PSE) ) > { > mfn += PFN_DOWN(addr & ((1UL << L2_PAGETABLE_SHIFT) - 1)); > @@ -90,10 +89,26 @@ void *do_page_walk(struct vcpu *v, unsigned long addr) > unmap_domain_page(l1t); > mfn = l1e_get_pfn(l1e); > if ( !(l1e_get_flags(l1e) & _PAGE_PRESENT) || !mfn_valid(_mfn(mfn)) ) > - return NULL; > + return INVALID_MFN; > > ret: > - return map_domain_page(_mfn(mfn)) + (addr & ~PAGE_MASK); > + return _mfn(mfn); > +} > + > +void *do_page_walk(struct vcpu *v, unsigned long addr) > +{ > + mfn_t mfn; > + unsigned long cr3; > + > + if ( !is_pv_vcpu(v) ) > + return NULL; > + > + cr3 = pagetable_get_pfn(v->arch.guest_table); > + mfn = _do_page_walk(cr3, addr); > + if ( mfn_eq(mfn, INVALID_MFN) ) > + return NULL; > + > + return map_domain_page(mfn) + (addr & ~PAGE_MASK); > } > > /* > diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h > index bef45e8e9f..224a94494a 100644 > --- a/xen/include/asm-x86/mm.h > +++ b/xen/include/asm-x86/mm.h > @@ -540,6 +540,7 @@ int new_guest_cr3(mfn_t mfn); > void make_cr3(struct vcpu *v, mfn_t mfn); > void update_cr3(struct vcpu *v); > int vcpu_destroy_pagetables(struct vcpu *); > +mfn_t _do_page_walk(unsigned long mfn, unsigned long addr); > void *do_page_walk(struct vcpu *v, unsigned long addr); > > int __sync_local_execstate(void); > diff --git a/xen/include/xen/livepatch.h b/xen/include/xen/livepatch.h > index 065c1a323a..e529f0e7c3 100644 > --- a/xen/include/xen/livepatch.h > +++ b/xen/include/xen/livepatch.h > @@ -72,6 +72,9 @@ int arch_livepatch_secure(const void *va, unsigned int pages, enum va_type types > > void arch_livepatch_init(void); > > +#include <xen/mm.h> /* For mfn_t decleration. */ > +mfn_t arch_livepatch_lookup_mfn(unsigned long addr); > + > #include <public/sysctl.h> /* For struct livepatch_func. */ > #include <asm/livepatch.h> > int arch_livepatch_verify_func(const struct livepatch_func *func); >
diff --git a/xen/arch/arm/livepatch.c b/xen/arch/arm/livepatch.c index e1d5d58f97..1771b3c558 100644 --- a/xen/arch/arm/livepatch.c +++ b/xen/arch/arm/livepatch.c @@ -13,9 +13,10 @@ #include <asm/livepatch.h> #include <asm/mm.h> -/* Override macros from asm/page.h to make them work with mfn_t */ -#undef virt_to_mfn -#define virt_to_mfn(va) _mfn(__virt_to_mfn(va)) +mfn_t arch_livepatch_lookup_mfn(unsigned long addr) +{ + return _mfn(__virt_to_mfn(addr)); +} void arch_livepatch_revive(void) { diff --git a/xen/arch/x86/livepatch.c b/xen/arch/x86/livepatch.c index 12287d445f..667573c6de 100644 --- a/xen/arch/x86/livepatch.c +++ b/xen/arch/x86/livepatch.c @@ -14,6 +14,16 @@ #include <asm/nmi.h> #include <asm/livepatch.h> +mfn_t arch_livepatch_lookup_mfn(unsigned long addr) +{ + unsigned long cr3 = read_cr3() >> PAGE_SHIFT; + + if ( !mfn_valid(_mfn(cr3)) ) + return INVALID_MFN; + + return _do_page_walk(cr3, addr); +} + void arch_livepatch_revive(void) { /* Nothing to do. */ diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c index 11746730b4..f8a963bbba 100644 --- a/xen/arch/x86/x86_64/mm.c +++ b/xen/arch/x86/x86_64/mm.c @@ -44,29 +44,28 @@ unsigned int __read_mostly m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START; l2_pgentry_t *compat_idle_pg_table_l2; -void *do_page_walk(struct vcpu *v, unsigned long addr) +mfn_t _do_page_walk(unsigned long mfn, unsigned long addr) { - unsigned long mfn = pagetable_get_pfn(v->arch.guest_table); l4_pgentry_t l4e, *l4t; l3_pgentry_t l3e, *l3t; l2_pgentry_t l2e, *l2t; l1_pgentry_t l1e, *l1t; - if ( !is_pv_vcpu(v) || !is_canonical_address(addr) ) - return NULL; + if ( !is_canonical_address(addr) ) + return INVALID_MFN; l4t = map_domain_page(_mfn(mfn)); l4e = l4t[l4_table_offset(addr)]; unmap_domain_page(l4t); if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) ) - return NULL; + return INVALID_MFN; l3t = map_l3t_from_l4e(l4e); l3e = l3t[l3_table_offset(addr)]; unmap_domain_page(l3t); mfn = l3e_get_pfn(l3e); if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) || !mfn_valid(_mfn(mfn)) ) - return NULL; + return INVALID_MFN; if ( (l3e_get_flags(l3e) & _PAGE_PSE) ) { mfn += PFN_DOWN(addr & ((1UL << L3_PAGETABLE_SHIFT) - 1)); @@ -78,7 +77,7 @@ void *do_page_walk(struct vcpu *v, unsigned long addr) unmap_domain_page(l2t); mfn = l2e_get_pfn(l2e); if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) || !mfn_valid(_mfn(mfn)) ) - return NULL; + return INVALID_MFN; if ( (l2e_get_flags(l2e) & _PAGE_PSE) ) { mfn += PFN_DOWN(addr & ((1UL << L2_PAGETABLE_SHIFT) - 1)); @@ -90,10 +89,26 @@ void *do_page_walk(struct vcpu *v, unsigned long addr) unmap_domain_page(l1t); mfn = l1e_get_pfn(l1e); if ( !(l1e_get_flags(l1e) & _PAGE_PRESENT) || !mfn_valid(_mfn(mfn)) ) - return NULL; + return INVALID_MFN; ret: - return map_domain_page(_mfn(mfn)) + (addr & ~PAGE_MASK); + return _mfn(mfn); +} + +void *do_page_walk(struct vcpu *v, unsigned long addr) +{ + mfn_t mfn; + unsigned long cr3; + + if ( !is_pv_vcpu(v) ) + return NULL; + + cr3 = pagetable_get_pfn(v->arch.guest_table); + mfn = _do_page_walk(cr3, addr); + if ( mfn_eq(mfn, INVALID_MFN) ) + return NULL; + + return map_domain_page(mfn) + (addr & ~PAGE_MASK); } /* diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h index bef45e8e9f..224a94494a 100644 --- a/xen/include/asm-x86/mm.h +++ b/xen/include/asm-x86/mm.h @@ -540,6 +540,7 @@ int new_guest_cr3(mfn_t mfn); void make_cr3(struct vcpu *v, mfn_t mfn); void update_cr3(struct vcpu *v); int vcpu_destroy_pagetables(struct vcpu *); +mfn_t _do_page_walk(unsigned long mfn, unsigned long addr); void *do_page_walk(struct vcpu *v, unsigned long addr); int __sync_local_execstate(void); diff --git a/xen/include/xen/livepatch.h b/xen/include/xen/livepatch.h index 065c1a323a..e529f0e7c3 100644 --- a/xen/include/xen/livepatch.h +++ b/xen/include/xen/livepatch.h @@ -72,6 +72,9 @@ int arch_livepatch_secure(const void *va, unsigned int pages, enum va_type types void arch_livepatch_init(void); +#include <xen/mm.h> /* For mfn_t decleration. */ +mfn_t arch_livepatch_lookup_mfn(unsigned long addr); + #include <public/sysctl.h> /* For struct livepatch_func. */ #include <asm/livepatch.h> int arch_livepatch_verify_func(const struct livepatch_func *func);