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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2] xen/arm: Find automatically the gnttab region for DOM0
Hi,
Ping?
Regards,
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 = ®[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
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