From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Tiejun" Subject: Re: [v6][PATCH 1/2] xen:x86:mm:p2m: introduce set_identity_p2m_entry Date: Wed, 30 Jul 2014 09:32:54 +0800 Message-ID: <53D84B46.9030206@intel.com> References: <1406683567-11600-1-git-send-email-tiejun.chen@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1406683567-11600-1-git-send-email-tiejun.chen@intel.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: JBeulich@suse.com, yang.z.zhang@intel.com, kevin.tian@intel.com Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org Please ignore this since another patch is missed in this thread. Sorry for any convenience. Thanks Tiejun On 2014/7/30 9:26, Tiejun Chen wrote: > Its used conveniently to create RMRR mapping in shared EPT case. > > Signed-off-by: Tiejun Chen > --- > xen/arch/x86/mm/p2m.c | 29 +++++++++++++++++++++++++++++ > xen/include/asm-x86/p2m.h | 3 +++ > 2 files changed, 32 insertions(+) > > v6: > > * Refactor set_identity_p2m_entry to make sense > > v5: > > * Rename this function as set_identity_p2m_entry() > * Get mfn directly inside set_identity_p2m_entry() > > v4: > > * new patch to combine get and set together to create RMRR mapping. > > diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c > index 642ec28..06bed7a 100644 > --- a/xen/arch/x86/mm/p2m.c > +++ b/xen/arch/x86/mm/p2m.c > @@ -858,6 +858,35 @@ int set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn) > return set_typed_p2m_entry(d, gfn, mfn, p2m_mmio_direct); > } > > +int set_identity_p2m_entry(struct domain *d, unsigned long gfn) > +{ > + p2m_type_t p2mt; > + p2m_access_t a; > + mfn_t mfn; > + struct p2m_domain *p2m = p2m_get_hostp2m(d); > + int ret = -EBUSY; > + > + gfn_lock(p2m, gfn, 0); > + > + mfn = p2m->get_entry(p2m, gfn, &p2mt, &a, 0, NULL); > + > + if ( !mfn_valid(mfn) ) > + ret = p2m_set_entry(p2m, gfn, _mfn(gfn), PAGE_ORDER_4K, p2m_mmio_direct, > + p2m_access_rw); > + else if ( mfn_x(mfn) == gfn && > + p2mt == p2m_mmio_direct && > + a == p2m_access_rw ) > + ret = 0; > + else > + printk(XENLOG_G_WARNING > + "Cannot identity map d%d:%lx, already mapped to %lx.\n", > + d->domain_id, gfn, mfn_x(mfn)); > + > + gfn_unlock(p2m, gfn, 0); > + > + return ret; > +} > + > /* Returns: 0 for success, -errno for failure */ > int clear_mmio_p2m_entry(struct domain *d, unsigned long gfn) > { > diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h > index 0ddbadb..d130f9a 100644 > --- a/xen/include/asm-x86/p2m.h > +++ b/xen/include/asm-x86/p2m.h > @@ -536,6 +536,9 @@ int p2m_is_logdirty_range(struct p2m_domain *, unsigned long start, > int set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn); > int clear_mmio_p2m_entry(struct domain *d, unsigned long gfn); > > +/* Set identity addresses in the p2m table (for pass-through) */ > +int set_identity_p2m_entry(struct domain *d, unsigned long gfn); > + > /* Add foreign mapping to the guest's p2m table. */ > int p2m_add_foreign(struct domain *tdom, unsigned long fgfn, > unsigned long gpfn, domid_t foreign_domid); >