[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 1/3] arm/arm64/xen: use C inlines for privcmd_call
On Thu, 21 Nov 2019, Pavel Tatashin wrote: > privcmd_call requires to enable access to userspace for the > duration of the hypercall. > > Currently, this is done via assembly macros. Change it to C > inlines instead. > > Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> I am OK with this. Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx> > --- > arch/arm/include/asm/assembler.h | 2 +- > arch/arm/include/asm/xen/hypercall.h | 10 +++++++++ > arch/arm/xen/enlighten.c | 2 +- > arch/arm/xen/hypercall.S | 4 ++-- > arch/arm64/include/asm/xen/hypercall.h | 28 ++++++++++++++++++++++++++ > arch/arm64/xen/hypercall.S | 19 ++--------------- > include/xen/arm/hypercall.h | 12 +++++------ > 7 files changed, 50 insertions(+), 27 deletions(-) > > diff --git a/arch/arm/include/asm/assembler.h > b/arch/arm/include/asm/assembler.h > index 99929122dad7..8e9262a0f016 100644 > --- a/arch/arm/include/asm/assembler.h > +++ b/arch/arm/include/asm/assembler.h > @@ -480,7 +480,7 @@ THUMB( orr \reg , \reg , #PSR_T_BIT ) > .macro uaccess_disable, tmp, isb=1 > #ifdef CONFIG_CPU_SW_DOMAIN_PAN > /* > - * Whenever we re-enter userspace, the domains should always be > + * Whenever we re-enter kernel, the domains should always be > * set appropriately. > */ > mov \tmp, #DACR_UACCESS_DISABLE > diff --git a/arch/arm/include/asm/xen/hypercall.h > b/arch/arm/include/asm/xen/hypercall.h > index 3522cbaed316..cac5bd9ef519 100644 > --- a/arch/arm/include/asm/xen/hypercall.h > +++ b/arch/arm/include/asm/xen/hypercall.h > @@ -1 +1,11 @@ > +#ifndef _ASM_ARM_XEN_HYPERCALL_H > +#define _ASM_ARM_XEN_HYPERCALL_H > #include <xen/arm/hypercall.h> > + > +static inline long privcmd_call(unsigned int call, unsigned long a1, > + unsigned long a2, unsigned long a3, > + unsigned long a4, unsigned long a5) > +{ > + return arch_privcmd_call(call, a1, a2, a3, a4, a5); > +} > +#endif /* _ASM_ARM_XEN_HYPERCALL_H */ > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > index dd6804a64f1a..e87280c6d25d 100644 > --- a/arch/arm/xen/enlighten.c > +++ b/arch/arm/xen/enlighten.c > @@ -440,4 +440,4 @@ EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw); > EXPORT_SYMBOL_GPL(HYPERVISOR_multicall); > EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist); > EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op); > -EXPORT_SYMBOL_GPL(privcmd_call); > +EXPORT_SYMBOL_GPL(arch_privcmd_call); > diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S > index b11bba542fac..277078c7da49 100644 > --- a/arch/arm/xen/hypercall.S > +++ b/arch/arm/xen/hypercall.S > @@ -94,7 +94,7 @@ HYPERCALL2(multicall); > HYPERCALL2(vm_assist); > HYPERCALL3(dm_op); > > -ENTRY(privcmd_call) > +ENTRY(arch_privcmd_call) > stmdb sp!, {r4} > mov r12, r0 > mov r0, r1 > @@ -119,4 +119,4 @@ ENTRY(privcmd_call) > > ldm sp!, {r4} > ret lr > -ENDPROC(privcmd_call); > +ENDPROC(arch_privcmd_call); > diff --git a/arch/arm64/include/asm/xen/hypercall.h > b/arch/arm64/include/asm/xen/hypercall.h > index 3522cbaed316..1a74fb28607f 100644 > --- a/arch/arm64/include/asm/xen/hypercall.h > +++ b/arch/arm64/include/asm/xen/hypercall.h > @@ -1 +1,29 @@ > +#ifndef _ASM_ARM64_XEN_HYPERCALL_H > +#define _ASM_ARM64_XEN_HYPERCALL_H > #include <xen/arm/hypercall.h> > +#include <linux/uaccess.h> > + > +static inline long privcmd_call(unsigned int call, unsigned long a1, > + unsigned long a2, unsigned long a3, > + unsigned long a4, unsigned long a5) > +{ > + long rv; > + > + /* > + * Privcmd calls are issued by the userspace. The kernel needs to > + * enable access to TTBR0_EL1 as the hypervisor would issue stage 1 > + * translations to user memory via AT instructions. Since AT > + * instructions are not affected by the PAN bit (ARMv8.1), we only > + * need the explicit uaccess_enable/disable if the TTBR0 PAN emulation > + * is enabled (it implies that hardware UAO and PAN disabled). > + */ > + uaccess_ttbr0_enable(); > + rv = arch_privcmd_call(call, a1, a2, a3, a4, a5); > + /* > + * Disable userspace access from kernel once the hyp call completed. > + */ > + uaccess_ttbr0_disable(); > + > + return rv; > +} > +#endif /* _ASM_ARM64_XEN_HYPERCALL_H */ > diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S > index c5f05c4a4d00..921611778d2a 100644 > --- a/arch/arm64/xen/hypercall.S > +++ b/arch/arm64/xen/hypercall.S > @@ -49,7 +49,6 @@ > > #include <linux/linkage.h> > #include <asm/assembler.h> > -#include <asm/asm-uaccess.h> > #include <xen/interface/xen.h> > > > @@ -86,27 +85,13 @@ HYPERCALL2(multicall); > HYPERCALL2(vm_assist); > HYPERCALL3(dm_op); > > -ENTRY(privcmd_call) > +ENTRY(arch_privcmd_call) > mov x16, x0 > mov x0, x1 > mov x1, x2 > mov x2, x3 > mov x3, x4 > mov x4, x5 > - /* > - * Privcmd calls are issued by the userspace. The kernel needs to > - * enable access to TTBR0_EL1 as the hypervisor would issue stage 1 > - * translations to user memory via AT instructions. Since AT > - * instructions are not affected by the PAN bit (ARMv8.1), we only > - * need the explicit uaccess_enable/disable if the TTBR0 PAN emulation > - * is enabled (it implies that hardware UAO and PAN disabled). > - */ > - uaccess_ttbr0_enable x6, x7, x8 > hvc XEN_IMM > - > - /* > - * Disable userspace access from kernel once the hyp call completed. > - */ > - uaccess_ttbr0_disable x6, x7 > ret > -ENDPROC(privcmd_call); > +ENDPROC(arch_privcmd_call); > diff --git a/include/xen/arm/hypercall.h b/include/xen/arm/hypercall.h > index b40485e54d80..624c8ad7e42a 100644 > --- a/include/xen/arm/hypercall.h > +++ b/include/xen/arm/hypercall.h > @@ -30,8 +30,8 @@ > * IN THE SOFTWARE. > */ > > -#ifndef _ASM_ARM_XEN_HYPERCALL_H > -#define _ASM_ARM_XEN_HYPERCALL_H > +#ifndef _ARM_XEN_HYPERCALL_H > +#define _ARM_XEN_HYPERCALL_H > > #include <linux/bug.h> > > @@ -41,9 +41,9 @@ > > struct xen_dm_op_buf; > > -long privcmd_call(unsigned call, unsigned long a1, > - unsigned long a2, unsigned long a3, > - unsigned long a4, unsigned long a5); > +long arch_privcmd_call(unsigned int call, unsigned long a1, > + unsigned long a2, unsigned long a3, > + unsigned long a4, unsigned long a5); > int HYPERVISOR_xen_version(int cmd, void *arg); > int HYPERVISOR_console_io(int cmd, int count, char *str); > int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int > count); > @@ -88,4 +88,4 @@ MULTI_mmu_update(struct multicall_entry *mcl, struct > mmu_update *req, > BUG(); > } > > -#endif /* _ASM_ARM_XEN_HYPERCALL_H */ > +#endif /* _ARM_XEN_HYPERCALL_H */ > -- > 2.24.0 > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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