| Message ID | 20220108004912.3820176-4-sstabellini@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | dom0less PV drivers | expand |
Hi Stefano, Stefano Stabellini <sstabellini@kernel.org> writes: > From: Stefano Stabellini <stefano.stabellini@xilinx.com> > > Introduce a new "xen,enhanced" dom0less property to enable/disable PV > driver interfaces for dom0less guests. Currently only "enabled" and > "disabled" are supported property values (and empty). Leave the option > open to implement further possible values in the future (e.g. > "xenstore" to enable only xenstore.) > > This patch only parses the property. Next patches will make use of it. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> > CC: Julien Grall <julien@xen.org> > CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com> > CC: Bertrand Marquis <bertrand.marquis@arm.com> > --- > docs/misc/arm/device-tree/booting.txt | 18 ++++++++++++++++++ > xen/arch/arm/domain_build.c | 5 +++++ > xen/arch/arm/include/asm/kernel.h | 3 +++ > 3 files changed, 26 insertions(+) > > diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt > index 71895663a4..38c29fb3d8 100644 > --- a/docs/misc/arm/device-tree/booting.txt > +++ b/docs/misc/arm/device-tree/booting.txt > @@ -169,6 +169,24 @@ with the following properties: > Please note that the SPI used for the virtual pl011 could clash with the > physical SPI of a physical device assigned to the guest. > > +- xen,enhanced > + > + A string property. Possible property values are: > + > + - "enabled" (or missing property value) > + Xen PV interfaces, including grant-table and xenstore, will be > + enabled for the VM. > + > + - "disabled" > + Xen PV interfaces are disabled. > + > + If the xen,enhanced property is present with no value, it defaults > + to "enabled". If the xen,enhanced property is not present, PV > + interfaces are disabled. > + > + In the future other possible property values might be added to > + enable only selected interfaces. > + > - nr_spis > > Optional. A 32-bit integer specifying the number of SPIs (Shared > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c > index 6931c022a2..96a94fa434 100644 > --- a/xen/arch/arm/domain_build.c > +++ b/xen/arch/arm/domain_build.c > @@ -2963,6 +2963,7 @@ static int __init construct_domU(struct domain *d, > const struct dt_device_node *node) > { > struct kernel_info kinfo = {}; > + const char *enhanced; > int rc; > u64 mem; > > @@ -2978,6 +2979,10 @@ static int __init construct_domU(struct domain *d, > > kinfo.vpl011 = dt_property_read_bool(node, "vpl011"); > > + rc = dt_property_read_string(node, "xen,enhanced", &enhanced); > + if ( rc == -EILSEQ || (rc == 0 && !strcmp(enhanced, "enabled")) ) Are you sure you need to check for -EILSEQ? From documentation for dt_property_read_string: * Returns 0 on * success, -EINVAL if the property does not exist, -ENODATA if property * doest not have value, and -EILSEQ if the string is not * null-terminated with the length of the property data. So, for me it looks like you need to check for -ENODATA. > + kinfo.enhanced = true; > + > if ( vcpu_create(d, 0) == NULL ) > return -ENOMEM; > > diff --git a/xen/arch/arm/include/asm/kernel.h b/xen/arch/arm/include/asm/kernel.h > index 874aa108a7..3275f7fbca 100644 > --- a/xen/arch/arm/include/asm/kernel.h > +++ b/xen/arch/arm/include/asm/kernel.h > @@ -36,6 +36,9 @@ struct kernel_info { > /* Enable pl011 emulation */ > bool vpl011; > > + /* Enable PV drivers */ > + bool enhanced; Maybe dom0less_enhanced will be better name? Or what about dom0? Should it have this option enabled? > + > /* GIC phandle */ > uint32_t phandle_gic;
On Tue, 11 Jan 2022, Volodymyr Babchuk wrote: > Hi Stefano, > > Stefano Stabellini <sstabellini@kernel.org> writes: > > > From: Stefano Stabellini <stefano.stabellini@xilinx.com> > > > > Introduce a new "xen,enhanced" dom0less property to enable/disable PV > > driver interfaces for dom0less guests. Currently only "enabled" and > > "disabled" are supported property values (and empty). Leave the option > > open to implement further possible values in the future (e.g. > > "xenstore" to enable only xenstore.) > > > > This patch only parses the property. Next patches will make use of it. > > > > Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> > > CC: Julien Grall <julien@xen.org> > > CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com> > > CC: Bertrand Marquis <bertrand.marquis@arm.com> > > --- > > docs/misc/arm/device-tree/booting.txt | 18 ++++++++++++++++++ > > xen/arch/arm/domain_build.c | 5 +++++ > > xen/arch/arm/include/asm/kernel.h | 3 +++ > > 3 files changed, 26 insertions(+) > > > > diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt > > index 71895663a4..38c29fb3d8 100644 > > --- a/docs/misc/arm/device-tree/booting.txt > > +++ b/docs/misc/arm/device-tree/booting.txt > > @@ -169,6 +169,24 @@ with the following properties: > > Please note that the SPI used for the virtual pl011 could clash with the > > physical SPI of a physical device assigned to the guest. > > > > +- xen,enhanced > > + > > + A string property. Possible property values are: > > + > > + - "enabled" (or missing property value) > > + Xen PV interfaces, including grant-table and xenstore, will be > > + enabled for the VM. > > + > > + - "disabled" > > + Xen PV interfaces are disabled. > > + > > + If the xen,enhanced property is present with no value, it defaults > > + to "enabled". If the xen,enhanced property is not present, PV > > + interfaces are disabled. > > + > > + In the future other possible property values might be added to > > + enable only selected interfaces. > > + > > - nr_spis > > > > Optional. A 32-bit integer specifying the number of SPIs (Shared > > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c > > index 6931c022a2..96a94fa434 100644 > > --- a/xen/arch/arm/domain_build.c > > +++ b/xen/arch/arm/domain_build.c > > @@ -2963,6 +2963,7 @@ static int __init construct_domU(struct domain *d, > > const struct dt_device_node *node) > > { > > struct kernel_info kinfo = {}; > > + const char *enhanced; > > int rc; > > u64 mem; > > > > @@ -2978,6 +2979,10 @@ static int __init construct_domU(struct domain *d, > > > > kinfo.vpl011 = dt_property_read_bool(node, "vpl011"); > > > > + rc = dt_property_read_string(node, "xen,enhanced", &enhanced); > > + if ( rc == -EILSEQ || (rc == 0 && !strcmp(enhanced, "enabled")) ) > > Are you sure you need to check for -EILSEQ? > > >From documentation for dt_property_read_string: > > * Returns 0 on > * success, -EINVAL if the property does not exist, -ENODATA if property > * doest not have value, and -EILSEQ if the string is not > * null-terminated with the length of the property data. > > So, for me it looks like you need to check for -ENODATA. That's interesting, I ran a few tests with: fdt set /chosen/domU0 xen,enhanced and I keep getting: (XEN) DEBUG construct_domU 3009 rc=-84 val=<NULL> And -84 is -EILSEQ. So I'll check for both -EILSEQ and -ENODATA to be safe. > > > + kinfo.enhanced = true; > > + > > if ( vcpu_create(d, 0) == NULL ) > > return -ENOMEM; > > > > diff --git a/xen/arch/arm/include/asm/kernel.h b/xen/arch/arm/include/asm/kernel.h > > index 874aa108a7..3275f7fbca 100644 > > --- a/xen/arch/arm/include/asm/kernel.h > > +++ b/xen/arch/arm/include/asm/kernel.h > > @@ -36,6 +36,9 @@ struct kernel_info { > > /* Enable pl011 emulation */ > > bool vpl011; > > > > + /* Enable PV drivers */ > > + bool enhanced; > > Maybe dom0less_enhanced will be better name? I am OK with that and maybe you are right, it is clearer. I'll keep the device tree option as "xen,enhanced" unless you meant to also change that too. > Or what about dom0? Should it have this option enabled? Yes, I think it makes sense to set it to true for dom0 too for consistency.
diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt index 71895663a4..38c29fb3d8 100644 --- a/docs/misc/arm/device-tree/booting.txt +++ b/docs/misc/arm/device-tree/booting.txt @@ -169,6 +169,24 @@ with the following properties: Please note that the SPI used for the virtual pl011 could clash with the physical SPI of a physical device assigned to the guest. +- xen,enhanced + + A string property. Possible property values are: + + - "enabled" (or missing property value) + Xen PV interfaces, including grant-table and xenstore, will be + enabled for the VM. + + - "disabled" + Xen PV interfaces are disabled. + + If the xen,enhanced property is present with no value, it defaults + to "enabled". If the xen,enhanced property is not present, PV + interfaces are disabled. + + In the future other possible property values might be added to + enable only selected interfaces. + - nr_spis Optional. A 32-bit integer specifying the number of SPIs (Shared diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index 6931c022a2..96a94fa434 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -2963,6 +2963,7 @@ static int __init construct_domU(struct domain *d, const struct dt_device_node *node) { struct kernel_info kinfo = {}; + const char *enhanced; int rc; u64 mem; @@ -2978,6 +2979,10 @@ static int __init construct_domU(struct domain *d, kinfo.vpl011 = dt_property_read_bool(node, "vpl011"); + rc = dt_property_read_string(node, "xen,enhanced", &enhanced); + if ( rc == -EILSEQ || (rc == 0 && !strcmp(enhanced, "enabled")) ) + kinfo.enhanced = true; + if ( vcpu_create(d, 0) == NULL ) return -ENOMEM; diff --git a/xen/arch/arm/include/asm/kernel.h b/xen/arch/arm/include/asm/kernel.h index 874aa108a7..3275f7fbca 100644 --- a/xen/arch/arm/include/asm/kernel.h +++ b/xen/arch/arm/include/asm/kernel.h @@ -36,6 +36,9 @@ struct kernel_info { /* Enable pl011 emulation */ bool vpl011; + /* Enable PV drivers */ + bool enhanced; + /* GIC phandle */ uint32_t phandle_gic;