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2015-09-11arm/xen: Enable user access to the kernel before issuing a privcmd callJulien Grall1-0/+15
When Xen is copying data to/from the guest it will check if the kernel has the right to do the access. If not, the hypercall will return an error. After the commit a5e090acbf545c0a3b04080f8a488b17ec41fe02 "ARM: software-based privileged-no-access support", the kernel can't access any longer the user space by default. This will result to fail on every hypercall made by the userspace (i.e via privcmd). We have to enable the userspace access and then restore the correct permission every time the privcmd is used to made an hypercall. I didn't find generic helpers to do a these operations, so the change is only arm32 specific. Reported-by: Riku Voipio <riku.voipio@linaro.org> Signed-off-by: Julien Grall <julien.grall@citrix.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+Russell King1-3/+3
ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-24arm: xen: implement multicall hypercall support.Ian Campbell1-0/+1
As part of this make the usual change to xen_ulong_t in place of unsigned long. This change has no impact on x86. The Linux definition of struct multicall_entry.result differs from the Xen definition, I think for good reasons, and used a long rather than an unsigned long. Therefore introduce a xen_long_t, which is a long on x86 architectures and a signed 64-bit integer on ARM. Use uint32_t nr_calls on x86 for consistency with the ARM definition. Build tested on amd64 and i386 builds. Runtime tested on ARM. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2013-07-04xen/arm and xen/arm64: implement HYPERVISOR_tmem_opStefano Stabellini1-0/+1
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-04-25xen/arm: implement HYPERVISOR_vcpu_opStefano Stabellini1-0/+1
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
2012-10-30xen/arm: use the __HVC macroStefano Stabellini1-9/+5
Use the new __HVC macro in hypercall.S. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-09-14xen/arm: hypercallsStefano Stabellini1-0/+106
Use r12 to pass the hypercall number to the hypervisor. We need a register to pass the hypercall number because we might not know it at compile time and HVC only takes an immediate argument. Among the available registers r12 seems to be the best choice because it is defined as "intra-procedure call scratch register". Use the ISS to pass an hypervisor specific tag. Changes in v2: - define an HYPERCALL macro for 5 arguments hypercall wrappers, even if at the moment is unused; - use ldm instead of pop; - fix up comments. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>