Hi guys > -----Original Message----- > From: Penny Zheng <[email protected]> > Sent: Tuesday, November 16, 2021 1:25 PM > To: Penny Zheng <[email protected]> > Cc: nd <[email protected]> > Subject: [PATCH v3 01/10] xen: introduce > XEN_DOMCTL_CDF_INTERNAL_directmap > > From: Stefano Stabellini <[email protected]> > > This commit introduces a new arm-specific flag > XEN_DOMCTL_CDF_INTERNAL_directmap to specify that a domain should > have its memory direct-map(guest physical address == physical address) at > domain creation. > > Since this flag is only available for domain created by XEN, not exposed to > the > toolstack, we name it with extra "INTERNAL" to distinguish from other public > XEN_DOMCTL_CDF_xxx flags, and add comments to warn developers not to > accidently use its bitfield when introducing new XEN_DOMCTL_CDF_xxx flag. > > Refine is_domain_direct_mapped to check whether the flag > XEN_DOMCTL_CDF_INTERNAL_directmap is set. > > Signed-off-by: Penny Zheng <[email protected]> > Signed-off-by: Stefano Stabellini <[email protected]> > --- > CC: [email protected] > CC: [email protected] > CC: George Dunlap <[email protected]> > CC: Ian Jackson <[email protected]> > CC: Wei Liu <[email protected]> > CC: "Roger Pau Monné" <[email protected]> > --- > v2 changes > - remove the introduce of internal flag > - remove flag direct_map since we already store this flag in d->options > - Refine is_domain_direct_mapped to check whether the flag > XEN_DOMCTL_CDF_directmap is set > - reword "1:1 direct-map" to just "direct-map" > --- > v3 changes > - move flag back to xen/include/xen/domain.h, to let it be only available for > domain created by XEN. > - name it with extra "INTERNAL" and add comments to warn developers not to > accidently use its bitfield when introducing new XEN_DOMCTL_CDF_xxx flag. > - reject this flag in x86'es arch_sanitise_domain_config() > --- > xen/arch/arm/domain.c | 3 ++- > xen/arch/arm/domain_build.c | 4 +++- > xen/arch/x86/domain.c | 6 ++++++ > xen/common/domain.c | 3 ++- > xen/include/asm-arm/domain.h | 4 ++-- > xen/include/public/domctl.h | 4 ++++ > xen/include/xen/domain.h | 3 +++ > 7 files changed, 22 insertions(+), 5 deletions(-) > > diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c index > 96e1b23550..d77265c03f 100644 > --- a/xen/arch/arm/domain.c > +++ b/xen/arch/arm/domain.c > @@ -629,7 +629,8 @@ int arch_sanitise_domain_config(struct > xen_domctl_createdomain *config) { > unsigned int max_vcpus; > unsigned int flags_required = (XEN_DOMCTL_CDF_hvm | > XEN_DOMCTL_CDF_hap); > - unsigned int flags_optional = (XEN_DOMCTL_CDF_iommu | > XEN_DOMCTL_CDF_vpmu); > + unsigned int flags_optional = (XEN_DOMCTL_CDF_iommu | > XEN_DOMCTL_CDF_vpmu | > + XEN_DOMCTL_CDF_INTERNAL_directmap); > > if ( (config->flags & ~flags_optional) != flags_required ) > { > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c > index 19487c79da..664c88ebe4 100644 > --- a/xen/arch/arm/domain_build.c > +++ b/xen/arch/arm/domain_build.c > @@ -3089,8 +3089,10 @@ static int __init construct_dom0(struct domain *d) > void __init create_dom0(void) { > struct domain *dom0; > + /* DOM0 has always its memory direct-map. */ > struct xen_domctl_createdomain dom0_cfg = { > - .flags = XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap, > + .flags = XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap | > + XEN_DOMCTL_CDF_INTERNAL_directmap, > .max_evtchn_port = -1, > .max_grant_frames = gnttab_dom0_frames(), > .max_maptrack_frames = -1, > diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c index > ef1812dc14..eba6502218 100644 > --- a/xen/arch/x86/domain.c > +++ b/xen/arch/x86/domain.c > @@ -692,6 +692,12 @@ int arch_sanitise_domain_config(struct > xen_domctl_createdomain *config) > return -EINVAL; > } > > + if ( config->flags & XEN_DOMCTL_CDF_INTERNAL_directmap ) > + { > + dprintk(XENLOG_INFO, "direct-map cannot be enabled yet\n"); > + return -EINVAL; > + } > + > return 0; > } > > diff --git a/xen/common/domain.c b/xen/common/domain.c index > 56d47dd664..13ac5950bc 100644 > --- a/xen/common/domain.c > +++ b/xen/common/domain.c > @@ -486,7 +486,8 @@ static int sanitise_domain_config(struct > xen_domctl_createdomain *config) > ~(XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap | > XEN_DOMCTL_CDF_s3_integrity | XEN_DOMCTL_CDF_oos_off | > XEN_DOMCTL_CDF_xs_domain | XEN_DOMCTL_CDF_iommu | > - XEN_DOMCTL_CDF_nested_virt | XEN_DOMCTL_CDF_vpmu) ) > + XEN_DOMCTL_CDF_nested_virt | XEN_DOMCTL_CDF_vpmu | > + XEN_DOMCTL_CDF_INTERNAL_directmap) ) > { > dprintk(XENLOG_INFO, "Unknown CDF flags %#x\n", config->flags); > return -EINVAL; > diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h > index 9b3647587a..4f2c3f09d4 100644 > --- a/xen/include/asm-arm/domain.h > +++ b/xen/include/asm-arm/domain.h > @@ -29,8 +29,8 @@ enum domain_type { > #define is_64bit_domain(d) (0) > #endif > > -/* The hardware domain has always its memory direct mapped. */ -#define > is_domain_direct_mapped(d) is_hardware_domain(d) > +#define is_domain_direct_mapped(d) \ > + (d->options & XEN_DOMCTL_CDF_INTERNAL_directmap) > > struct vtimer { > struct vcpu *v; > diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h index > 1c21d4dc75..054e545c97 100644 > --- a/xen/include/public/domctl.h > +++ b/xen/include/public/domctl.h > @@ -72,6 +72,10 @@ struct xen_domctl_createdomain { > #define XEN_DOMCTL_CDF_nested_virt (1U << > _XEN_DOMCTL_CDF_nested_virt) > /* Should we expose the vPMU to the guest? */ > #define XEN_DOMCTL_CDF_vpmu (1U << 7) > +/* > + * Be aware that bit 8 has already been occupied by flag > + * XEN_DOMCTL_CDF_INTERNAL_directmap, defined in > xen/include/xen/domain.h. > + */ > > /* Max XEN_DOMCTL_CDF_* constant. Used for ABI checking. */ #define > XEN_DOMCTL_CDF_MAX XEN_DOMCTL_CDF_vpmu diff --git > a/xen/include/xen/domain.h b/xen/include/xen/domain.h index > 160c8dbdab..2b9edfdcee 100644 > --- a/xen/include/xen/domain.h > +++ b/xen/include/xen/domain.h > @@ -28,6 +28,9 @@ void getdomaininfo(struct domain *d, struct > xen_domctl_getdomaininfo *info); void arch_get_domain_info(const struct > domain *d, > struct xen_domctl_getdomaininfo *info); > > +/* Should domain memory be directly mapped? */ > +#define XEN_DOMCTL_CDF_INTERNAL_directmap (1U << 8) > +
I run into some trouble with defining this flag internal in the new serie. Let me explain in details here: 1. Currently XEN_DOMCTL_CDF_MAX is set to XEN_DOMCTL_CDF_vpmu. So we can say that XEN_DOMCTL_CDF_MAX knows that there are 8 CDF flags(0 to 7). The corresponding ocaml tool has a list of CDF flags and currently it knows that there are 8 CDF flags: https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=tools/ocaml/libs/xc/xenctrl.ml;h=7503031d8f61c2dbcd4aa803738c83e10dfb7bb8;hb=HEAD#l64 This tool performs a check to see if the XEN_DOMCTL_CDF_MAX is equal to the number of entries in domain_create_flag. 2. Here we are reserving bit 8 for internal flag XEN_DOMCTL_CDF_INTERNAL_directmap. As this is internal flag, I do not want to modify XEN_DOMCTL_CDF_MAX. 3. Everything is perfect until someone tries to add another global CDF flag: #define XEN_DOMCTL_CDF_next_flag (1<<9) #define XEN_DOMCTL_CDF_MAX XEN_DOMCTL_CDF_next_flag XEN_DOMCTL_CDF_MAX shows right now that there are 10 flags but ocaml tool sees only 9. then we are getting build error. Hmm, would you please help me find a way to fix this dilemma, thx. > /* > * Arch-specifics. > */ > -- > 2.25.1 Cheers, Penny Zheng
