| Message ID | 1370273624-26976-5-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jun 03, 2013 at 04:33:44PM +0100, Stefano Stabellini wrote: > --- /dev/null > +++ b/arch/arm64/xen/hypercall.S ... > +/* > + * The Xen hypercall calling convention is very similar to the ARM AEBI > + * procedure calling convention: the first paramter is passed in x0, the > + * second in x1, the third in x2 and the fourth in x3. Considering that > + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed > + * in rx, differently from the procedure calling convention of using the > + * stack for that case. You may want to use the AArch64 ABI here where parameters are passed in x0-x7, return in x0. BTW, I think it's missing a MAINTAINERS file update. Otherwise, the series looks good. How do you plan to upstream this?
On Mon, 2013-06-03 at 17:25 +0100, Catalin Marinas wrote: > On Mon, Jun 03, 2013 at 04:33:44PM +0100, Stefano Stabellini wrote: > > --- /dev/null > > +++ b/arch/arm64/xen/hypercall.S > ... > > +/* > > + * The Xen hypercall calling convention is very similar to the ARM AEBI > > + * procedure calling convention: the first paramter is passed in x0, the > > + * second in x1, the third in x2 and the fourth in x3. Considering that > > + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed parameter > > + * in rx, differently from the procedure calling convention of using the ^x4 not rx > > + * stack for that case. > > You may want to use the AArch64 ABI here where parameters are passed in > x0-x7, return in x0. I think that is actually what we are doing (up to 5 arguments), the "Considering that ..." bit at the end is a left over of the 32 bit version I think. > > BTW, I think it's missing a MAINTAINERS file update. > > Otherwise, the series looks good. How do you plan to upstream this? >
On Mon, Jun 03, 2013 at 05:37:35PM +0100, Ian Campbell wrote: > On Mon, 2013-06-03 at 17:25 +0100, Catalin Marinas wrote: > > On Mon, Jun 03, 2013 at 04:33:44PM +0100, Stefano Stabellini wrote: > > > --- /dev/null > > > +++ b/arch/arm64/xen/hypercall.S > > ... > > > +/* > > > + * The Xen hypercall calling convention is very similar to the ARM AEBI > > > + * procedure calling convention: the first paramter is passed in x0, the > > > + * second in x1, the third in x2 and the fourth in x3. Considering that > > > + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed > > parameter > > > > + * in rx, differently from the procedure calling convention of using the > > ^x4 not rx > > > > + * stack for that case. > > > > You may want to use the AArch64 ABI here where parameters are passed in > > x0-x7, return in x0. > > I think that is actually what we are doing (up to 5 arguments), the > "Considering that ..." bit at the end is a left over of the 32 bit > version I think. Yes, only the comment needs updating.
On Mon, 3 Jun 2013, Catalin Marinas wrote: > On Mon, Jun 03, 2013 at 04:33:44PM +0100, Stefano Stabellini wrote: > > --- /dev/null > > +++ b/arch/arm64/xen/hypercall.S > ... > > +/* > > + * The Xen hypercall calling convention is very similar to the ARM AEBI > > + * procedure calling convention: the first paramter is passed in x0, the > > + * second in x1, the third in x2 and the fourth in x3. Considering that > > + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed > > + * in rx, differently from the procedure calling convention of using the > > + * stack for that case. > > You may want to use the AArch64 ABI here where parameters are passed in > x0-x7, return in x0. We already do this, we just need to update the comment. > BTW, I think it's missing a MAINTAINERS file update. Yep, I'll make those changes. > Otherwise, the series looks good. How do you plan to upstream this? Good question. Traditionally Xen stuff goes to Linus directly via one of the Xen trees (Konrad's or mine), but since this is the very first Xen patch series for arm64 if you prefer I can submit a pull request to you instead. Just let me know, I am happy either way. In any case, are you OK with sending it upstream during the next merge window?
> BTW, I think it's missing a MAINTAINERS file update.
I presume you mean that Stefano should have the MAINTAINERS file updated to include
him being the maintainer of arch/arm64/xen* ?
On Tue, Jun 04, 2013 at 03:47:41PM +0100, Konrad Rzeszutek Wilk wrote: > > BTW, I think it's missing a MAINTAINERS file update. > > I presume you mean that Stefano should have the MAINTAINERS file updated to include > him being the maintainer of arch/arm64/xen* ? Yes (or whoever will maintain Xen for arm64).
On Mon, Jun 03, 2013 at 05:51:53PM +0100, Stefano Stabellini wrote: > On Mon, 3 Jun 2013, Catalin Marinas wrote: > > Otherwise, the series looks good. How do you plan to upstream this? > > Good question. > Traditionally Xen stuff goes to Linus directly via one of the Xen trees > (Konrad's or mine), but since this is the very first Xen patch series > for arm64 if you prefer I can submit a pull request to you instead. > Just let me know, I am happy either way. I can take the first series and subsequent merges can go via the Xen tree (KVM has a similar approach). > In any case, are you OK with sending it upstream during the next merge > window? Yes, if I get a pull request in time ;)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 56b3f6d..b5d6ada 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -182,6 +182,16 @@ config HW_PERF_EVENTS source "mm/Kconfig" +config XEN_DOM0 + def_bool y + depends on XEN + +config XEN + bool "Xen guest support on ARM64 (EXPERIMENTAL)" + depends on ARM64 && OF + help + Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. + endmenu menu "Boot options" diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index c95c5cb..79dd13d 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -37,6 +37,7 @@ TEXT_OFFSET := 0x00080000 export TEXT_OFFSET GZFLAGS core-y += arch/arm64/kernel/ arch/arm64/mm/ +core-$(CONFIG_XEN) += arch/arm64/xen/ libs-y := arch/arm64/lib/ $(libs-y) libs-y += $(LIBGCC) diff --git a/arch/arm64/xen/Makefile b/arch/arm64/xen/Makefile new file mode 100644 index 0000000..be24040 --- /dev/null +++ b/arch/arm64/xen/Makefile @@ -0,0 +1,2 @@ +xen-arm-y += $(addprefix ../../arm/xen/, enlighten.o grant-table.o) +obj-y := xen-arm.o hypercall.o diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S new file mode 100644 index 0000000..8e362cc --- /dev/null +++ b/arch/arm64/xen/hypercall.S @@ -0,0 +1,94 @@ +/****************************************************************************** + * hypercall.S + * + * Xen hypercall wrappers + * + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +/* + * The Xen hypercall calling convention is very similar to the ARM AEBI + * procedure calling convention: the first paramter is passed in x0, the + * second in x1, the third in x2 and the fourth in x3. Considering that + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed + * in rx, differently from the procedure calling convention of using the + * stack for that case. + * + * The hypercall number is passed in x16. + * + * The return value is in x0. + * + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM + * hypercall tag. + * + * Parameter structs passed to hypercalls are laid out according to + * the ARM EABI standard. + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <xen/interface/xen.h> + + +#define XEN_IMM 0xEA1 + +#define HYPERCALL_SIMPLE(hypercall) \ +ENTRY(HYPERVISOR_##hypercall) \ + mov x16, #__HYPERVISOR_##hypercall; \ + hvc XEN_IMM; \ + ret; \ +ENDPROC(HYPERVISOR_##hypercall) + +#define HYPERCALL0 HYPERCALL_SIMPLE +#define HYPERCALL1 HYPERCALL_SIMPLE +#define HYPERCALL2 HYPERCALL_SIMPLE +#define HYPERCALL3 HYPERCALL_SIMPLE +#define HYPERCALL4 HYPERCALL_SIMPLE +#define HYPERCALL5 HYPERCALL_SIMPLE + + .text + +HYPERCALL2(xen_version); +HYPERCALL3(console_io); +HYPERCALL3(grant_table_op); +HYPERCALL2(sched_op); +HYPERCALL2(event_channel_op); +HYPERCALL2(hvm_op); +HYPERCALL2(memory_op); +HYPERCALL2(physdev_op); +HYPERCALL3(vcpu_op); + +ENTRY(privcmd_call) + mov x16, x0 + mov x0, x1 + mov x1, x2 + mov x2, x3 + mov x3, x4 + mov x4, x5 + hvc XEN_IMM + ret +ENDPROC(privcmd_call);
Introduce CONFIG_XEN and the implementation of hypercall.S (that is the only ARMv8 specific code in Xen support for ARM). Compile enlighten.c and grant_table.c from arch/arm. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Changes in v2: - remove depends on !GENERIC_ATOMIC64; - compile enlighten.c and grant_table.c from arch/arm directly; - fix the privcmd implementation: according to the aarch64 procedure call ABI the first 7 parameters are passed on registers so we don't need to push/pop anything. --- arch/arm64/Kconfig | 10 +++++ arch/arm64/Makefile | 1 + arch/arm64/xen/Makefile | 2 + arch/arm64/xen/hypercall.S | 94 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 107 insertions(+), 0 deletions(-) create mode 100644 arch/arm64/xen/Makefile create mode 100644 arch/arm64/xen/hypercall.S