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Re: [Xen-devel] [PATCH v2] xen/arm: Find automatically the gnttab region for DOM0

On Thu, 2 Jul 2015, Julien Grall wrote: > Hi, > > Ping? > The patch looks very nice. Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> > > On 17/06/15 14:58, Julien Grall wrote: > > Currently, the grant table region is hardcoded per-platform. When a new > > board is coming up, we have to check the spec in order to find a space > > in the memory layout free. Depending on the platform it may be tedious. > > > > A good candidate for the gnttab region is the one used by Xen binary as > > some part will never be mapped to the DOM0 address, MMIO are mapped 1:1 > > and the RAM will be either: > > - direct mapped: 1:1 mapping is used => no problem > > - non direct mapped: Xen always relocates himself as high as possible > > (limited to 4GB on ARM32) and the RAM bank are filled from the first > > one. It's very unlikely that the gnttab region will overlap with the > > RAM. Although for safety a check may be necessary when we will reenable > > the option. > > > > Furthermore, there is plenty of space to contain a big gnttab, the default > > size is 32 frame (i.e 128KB) but it can be changed via a command option. > > > > It's not possible to use the whole region used by Xen, as some part of > > the binary will be freed after Xen boot and can be used by DOM0 and other > > guest. A sensible choice is the text secion as it will always reside in > > memory never be mapped to the guest and the size is big enough (~300KB > > on ARM64). It could be extended later to use other contiguous sections > > such as data... > > > > Note that on ARM64, the grant table region may be after 4GB (Xen is > > relocated to the highest address) using DOM0 32 bit with short page table > > may not work. Although, I don't think this is a big deal as device may not > > work and/or the RAM is too high due to the 1:1 mapping. > > > > This patch also drop the platforms thunderx and xilinx-zynqmp which became > > dummy by dropping the hardcoding DOM0 grant table region. > > > > Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx> > > > > --- > > Changes in v2: > > - Typoes > > - Message and comment improvement > > --- > > xen/arch/arm/domain_build.c | 47 > > ++++++++++++++++++++++++++++------ > > xen/arch/arm/kernel.h | 4 +++ > > xen/arch/arm/platform.c | 14 ---------- > > xen/arch/arm/platforms/Makefile | 2 -- > > xen/arch/arm/platforms/midway.c | 3 --- > > xen/arch/arm/platforms/omap5.c | 6 ----- > > xen/arch/arm/platforms/rcar2.c | 3 --- > > xen/arch/arm/platforms/seattle.c | 3 --- > > xen/arch/arm/platforms/sunxi.c | 3 --- > > xen/arch/arm/platforms/thunderx.c | 41 ----------------------------- > > xen/arch/arm/platforms/vexpress.c | 2 -- > > xen/arch/arm/platforms/xgene-storm.c | 3 --- > > xen/arch/arm/platforms/xilinx-zynqmp.c | 41 ----------------------------- > > xen/include/asm-arm/platform.h | 7 ----- > > 14 files changed, 43 insertions(+), 136 deletions(-) > > delete mode 100644 xen/arch/arm/platforms/thunderx.c > > delete mode 100644 xen/arch/arm/platforms/xilinx-zynqmp.c > > > > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c > > index e9cb8a9..d8b775f 100644 > > --- a/xen/arch/arm/domain_build.c > > +++ b/xen/arch/arm/domain_build.c > > @@ -21,6 +21,7 @@ > > > > #include <asm/gic.h> > > #include <xen/irq.h> > > +#include <xen/grant_table.h> > > #include "kernel.h" > > > > static unsigned int __initdata opt_dom0_max_vcpus; > > @@ -605,8 +606,8 @@ static int make_memory_node(const struct domain *d, > > return res; > > } > > > > -static int make_hypervisor_node(struct domain *d, > > - void *fdt, const struct dt_device_node > > *parent) > > +static int make_hypervisor_node(const struct kernel_info *kinfo, > > + const struct dt_device_node *parent) > > { > > const char compat[] = > > > > "xen,xen-"__stringify(XEN_VERSION)"."__stringify(XEN_SUBVERSION)"\0" > > @@ -615,9 +616,10 @@ static int make_hypervisor_node(struct domain *d, > > gic_interrupt_t intr; > > __be32 *cells; > > int res; > > + /* Convenience alias */ > > int addrcells = dt_n_addr_cells(parent); > > int sizecells = dt_n_size_cells(parent); > > - paddr_t gnttab_start, gnttab_size; > > + void *fdt = kinfo->fdt; > > > > DPRINT("Create hypervisor node\n"); > > > > @@ -639,12 +641,9 @@ static int make_hypervisor_node(struct domain *d, > > if ( res ) > > return res; > > > > - platform_dom0_gnttab(&gnttab_start, &gnttab_size); > > - DPRINT(" Grant table range: %#"PRIpaddr"-%#"PRIpaddr"\n", > > - gnttab_start, gnttab_start + gnttab_size); > > /* reg 0 is grant table space */ > > cells = &reg[0]; > > - dt_set_range(&cells, parent, gnttab_start, gnttab_size); > > + dt_set_range(&cells, parent, kinfo->gnttab_start, kinfo->gnttab_size); > > res = fdt_property(fdt, "reg", reg, > > dt_cells_to_size(addrcells + sizecells)); > > if ( res ) > > @@ -1192,7 +1191,7 @@ static int handle_node(struct domain *d, struct > > kernel_info *kinfo, > > > > if ( node == dt_host ) > > { > > - res = make_hypervisor_node(d, kinfo->fdt, node); > > + res = make_hypervisor_node(kinfo, node); > > if ( res ) > > return res; > > > > @@ -1368,6 +1367,37 @@ static void evtchn_fixup(struct domain *d, struct > > kernel_info *kinfo) > > panic("Cannot fix up \"interrupts\" property of the hypervisor > > node"); > > } > > > > +static void __init find_gnttab_region(struct domain *d, > > + struct kernel_info *kinfo) > > +{ > > + /* > > + * The region used by Xen on the memory will never be mapped in DOM0 > > + * memory layout. Therefore it can be used for the grant table. > > + * > > + * Only use the text section as it's always present and will contain > > + * enough space for a large grant table > > + */ > > + kinfo->gnttab_start = __pa(_stext); > > + kinfo->gnttab_size = (_etext - _stext) & PAGE_MASK; > > + > > + /* Make sure the grant table will fit in the region */ > > + if ( (kinfo->gnttab_size >> PAGE_SHIFT) < max_grant_frames ) > > + panic("Cannot find a space for the grant table region\n"); > > + > > +#ifdef CONFIG_ARM_32 > > + /* > > + * The gnttab region must be under 4GB in order to work with DOM0 > > + * using short page table. > > + * In practice it's always the case because Xen is always located > > + * below 4GB, but be safe. > > + */ > > + BUG_ON((kinfo->gnttab_start + kinfo->gnttab_size) > GB(4)); > > +#endif > > + > > + printk("Grant table range: %#"PRIpaddr"-%#"PRIpaddr"\n", > > + kinfo->gnttab_start, kinfo->gnttab_start + kinfo->gnttab_size); > > +} > > + > > int construct_dom0(struct domain *d) > > { > > struct kernel_info kinfo = {}; > > @@ -1405,6 +1435,7 @@ int construct_dom0(struct domain *d) > > #endif > > > > allocate_memory(d, &kinfo); > > + find_gnttab_region(d, &kinfo); > > > > rc = prepare_dtb(d, &kinfo); > > if ( rc < 0 ) > > diff --git a/xen/arch/arm/kernel.h b/xen/arch/arm/kernel.h > > index 0050dfb..c1b07d4 100644 > > --- a/xen/arch/arm/kernel.h > > +++ b/xen/arch/arm/kernel.h > > @@ -22,6 +22,10 @@ struct kernel_info { > > /* kernel entry point */ > > paddr_t entry; > > > > + /* grant table region */ > > + paddr_t gnttab_start; > > + paddr_t gnttab_size; > > + > > /* boot blob load addresses */ > > const struct bootmodule *kernel_bootmodule, *initrd_bootmodule; > > paddr_t dtb_paddr; > > diff --git a/xen/arch/arm/platform.c b/xen/arch/arm/platform.c > > index 70c1388..0af6d57 100644 > > --- a/xen/arch/arm/platform.c > > +++ b/xen/arch/arm/platform.c > > @@ -147,20 +147,6 @@ bool_t platform_device_is_blacklisted(const struct > > dt_device_node *node) > > return (dt_match_node(blacklist, node) != NULL); > > } > > > > -void platform_dom0_gnttab(paddr_t *start, paddr_t *size) > > -{ > > - if ( platform && platform->dom0_gnttab_size ) > > - { > > - *start = platform->dom0_gnttab_start; > > - *size = platform->dom0_gnttab_size; > > - } > > - else > > - { > > - *start = 0xb0000000; > > - *size = 0x20000; > > - } > > -} > > - > > /* > > * Local variables: > > * mode: C > > diff --git a/xen/arch/arm/platforms/Makefile > > b/xen/arch/arm/platforms/Makefile > > index e7f2a43..e173fec 100644 > > --- a/xen/arch/arm/platforms/Makefile > > +++ b/xen/arch/arm/platforms/Makefile > > @@ -6,6 +6,4 @@ obj-$(CONFIG_ARM_32) += omap5.o > > obj-$(CONFIG_ARM_32) += sunxi.o > > obj-$(CONFIG_ARM_32) += rcar2.o > > obj-$(CONFIG_ARM_64) += seattle.o > > -obj-$(CONFIG_ARM_64) += thunderx.o > > obj-$(CONFIG_ARM_64) += xgene-storm.o > > -obj-$(CONFIG_ARM_64) += xilinx-zynqmp.o > > diff --git a/xen/arch/arm/platforms/midway.c > > b/xen/arch/arm/platforms/midway.c > > index 42f7697..b221279 100644 > > --- a/xen/arch/arm/platforms/midway.c > > +++ b/xen/arch/arm/platforms/midway.c > > @@ -51,9 +51,6 @@ static const char * const midway_dt_compat[] __initconst = > > PLATFORM_START(midway, "CALXEDA MIDWAY") > > .compatible = midway_dt_compat, > > .reset = midway_reset, > > - > > - .dom0_gnttab_start = 0xff800000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > /* > > diff --git a/xen/arch/arm/platforms/omap5.c b/xen/arch/arm/platforms/omap5.c > > index e7bf30d..a49ba62 100644 > > --- a/xen/arch/arm/platforms/omap5.c > > +++ b/xen/arch/arm/platforms/omap5.c > > @@ -161,9 +161,6 @@ PLATFORM_START(omap5, "TI OMAP5") > > .specific_mapping = omap5_specific_mapping, > > .smp_init = omap5_smp_init, > > .cpu_up = cpu_up_send_sgi, > > - > > - .dom0_gnttab_start = 0x4b000000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > PLATFORM_START(dra7, "TI DRA7") > > @@ -171,9 +168,6 @@ PLATFORM_START(dra7, "TI DRA7") > > .init_time = omap5_init_time, > > .cpu_up = cpu_up_send_sgi, > > .smp_init = omap5_smp_init, > > - > > - .dom0_gnttab_start = 0x4b000000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > /* > > diff --git a/xen/arch/arm/platforms/rcar2.c b/xen/arch/arm/platforms/rcar2.c > > index aef544c..bb25751 100644 > > --- a/xen/arch/arm/platforms/rcar2.c > > +++ b/xen/arch/arm/platforms/rcar2.c > > @@ -56,9 +56,6 @@ PLATFORM_START(rcar2, "Renesas R-Car Gen2") > > .compatible = rcar2_dt_compat, > > .cpu_up = cpu_up_send_sgi, > > .smp_init = rcar2_smp_init, > > - > > - .dom0_gnttab_start = 0xc0000000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > /* > > diff --git a/xen/arch/arm/platforms/seattle.c > > b/xen/arch/arm/platforms/seattle.c > > index 6cc5362..86dce91 100644 > > --- a/xen/arch/arm/platforms/seattle.c > > +++ b/xen/arch/arm/platforms/seattle.c > > @@ -45,9 +45,6 @@ PLATFORM_START(seattle, "SEATTLE") > > .compatible = seattle_dt_compat, > > .reset = seattle_system_reset, > > .poweroff = seattle_system_off, > > - > > - .dom0_gnttab_start = 0xe1700000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > /* > > diff --git a/xen/arch/arm/platforms/sunxi.c b/xen/arch/arm/platforms/sunxi.c > > index 89d8290..0ba7b3d 100644 > > --- a/xen/arch/arm/platforms/sunxi.c > > +++ b/xen/arch/arm/platforms/sunxi.c > > @@ -69,9 +69,6 @@ PLATFORM_START(sunxi, "Allwinner A20") > > .compatible = sunxi_dt_compat, > > .blacklist_dev = sunxi_blacklist_dev, > > .reset = sunxi_reset, > > - > > - .dom0_gnttab_start = 0x01d00000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > /* > > diff --git a/xen/arch/arm/platforms/thunderx.c > > b/xen/arch/arm/platforms/thunderx.c > > deleted file mode 100644 > > index be6f24f..0000000 > > --- a/xen/arch/arm/platforms/thunderx.c > > +++ /dev/null > > @@ -1,41 +0,0 @@ > > -/* > > - * xen/arch/arm/platforms/thunderx.c > > - * > > - * Cavium Thunder specific settings > > - * > > - * Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx> > > - * Copyright (c) 2015 Cavium Inc. > > - * > > - * This program is free software; you can redistribute it and/or modify > > - * it under the terms of the GNU General Public License as published by > > - * the Free Software Foundation; either version 2 of the License, or > > - * (at your option) any later version. > > - * > > - * This program is distributed in the hope that it will be useful, > > - * but WITHOUT ANY WARRANTY; without even the implied warranty of > > - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > - * GNU General Public License for more details. > > - */ > > - > > -#include <asm/platform.h> > > - > > -static const char * const thunderx_dt_compat[] __initconst = > > -{ > > - "cavium,thunder-88xx", > > - NULL > > -}; > > - > > -PLATFORM_START(thunderx, "THUNDERX") > > - .compatible = thunderx_dt_compat, > > - .dom0_gnttab_start = 0x40000000000, > > - .dom0_gnttab_size = 0x20000, > > -PLATFORM_END > > - > > -/* > > - * Local variables: > > - * mode: C > > - * c-file-style: "BSD" > > - * c-basic-offset: 4 > > - * indent-tabs-mode: nil > > - * End: > > - */ > > diff --git a/xen/arch/arm/platforms/vexpress.c > > b/xen/arch/arm/platforms/vexpress.c > > index ce66935..8e6a4ea 100644 > > --- a/xen/arch/arm/platforms/vexpress.c > > +++ b/xen/arch/arm/platforms/vexpress.c > > @@ -176,8 +176,6 @@ PLATFORM_START(vexpress, "VERSATILE EXPRESS") > > #endif > > .reset = vexpress_reset, > > .blacklist_dev = vexpress_blacklist_dev, > > - .dom0_gnttab_start = 0x10000000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > /* > > diff --git a/xen/arch/arm/platforms/xgene-storm.c > > b/xen/arch/arm/platforms/xgene-storm.c > > index 1362bea..26754b5 100644 > > --- a/xen/arch/arm/platforms/xgene-storm.c > > +++ b/xen/arch/arm/platforms/xgene-storm.c > > @@ -266,9 +266,6 @@ PLATFORM_START(xgene_storm, "APM X-GENE STORM") > > .reset = xgene_storm_reset, > > .quirks = xgene_storm_quirks, > > .specific_mapping = xgene_storm_specific_mapping, > > - > > - .dom0_gnttab_start = 0x1f800000, > > - .dom0_gnttab_size = 0x20000, > > PLATFORM_END > > > > /* > > diff --git a/xen/arch/arm/platforms/xilinx-zynqmp.c > > b/xen/arch/arm/platforms/xilinx-zynqmp.c > > deleted file mode 100644 > > index d03fb36..0000000 > > --- a/xen/arch/arm/platforms/xilinx-zynqmp.c > > +++ /dev/null > > @@ -1,41 +0,0 @@ > > -/* > > - * xen/arch/arm/platforms/xilinx-zynqmp.c > > - * > > - * Xilinx ZynqMP setup > > - * > > - * Copyright (c) 2015 Xilinx Inc. > > - * Written by Edgar E. Iglesias <edgar.iglesias@xxxxxxxxxx> > > - * > > - * This program is free software; you can redistribute it and/or modify > > - * it under the terms of the GNU General Public License as published by > > - * the Free Software Foundation; either version 2 of the License, or > > - * (at your option) any later version. > > - * > > - * This program is distributed in the hope that it will be useful, > > - * but WITHOUT ANY WARRANTY; without even the implied warranty of > > - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > - * GNU General Public License for more details. > > - */ > > - > > -#include <asm/platform.h> > > - > > -static const char * const zynqmp_dt_compat[] __initconst = > > -{ > > - "xlnx,zynqmp", > > - NULL > > -}; > > - > > -PLATFORM_START(xgene_storm, "Xilinx ZynqMP") > > - .compatible = zynqmp_dt_compat, > > - .dom0_gnttab_start = 0xf0000000, > > - .dom0_gnttab_size = 0x20000, > > -PLATFORM_END > > - > > -/* > > - * Local variables: > > - * mode: C > > - * c-file-style: "BSD" > > - * c-basic-offset: 4 > > - * indent-tabs-mode: nil > > - * End: > > - */ > > diff --git a/xen/include/asm-arm/platform.h b/xen/include/asm-arm/platform.h > > index 283b50f..b8fc5ac 100644 > > --- a/xen/include/asm-arm/platform.h > > +++ b/xen/include/asm-arm/platform.h > > @@ -37,12 +37,6 @@ struct platform_desc { > > * List of devices which must not pass-through to a guest > > */ > > const struct dt_device_match *blacklist_dev; > > - /* > > - * The location of a region of physical address space which dom0 > > - * can use for grant table mappings. If size is zero defaults to > > - * 0xb0000000-0xb0020000. > > - */ > > - paddr_t dom0_gnttab_start, dom0_gnttab_size; > > }; > > > > /* > > @@ -63,7 +57,6 @@ void platform_poweroff(void); > > bool_t platform_has_quirk(uint32_t quirk); > > bool_t platform_device_is_blacklisted(const struct dt_device_node *node); > > unsigned int platform_dom0_evtchn_ppi(void); > > -void platform_dom0_gnttab(paddr_t *start, paddr_t *size); > > > > #define PLATFORM_START(_name, _namestr) \ > > static const struct platform_desc __plat_desc_##_name __used \ > > > > > -- > Julien Grall > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel

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