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Message-Id: <20200102211357.8042-3-pasha.tatashin@soleen.com>
Date: Thu, 2 Jan 2020 16:13:53 -0500
From: Pavel Tatashin <pasha.tatashin@...een.com>
To: pasha.tatashin@...een.com, jmorris@...ei.org, sashal@...nel.org,
linux-kernel@...r.kernel.org, catalin.marinas@....com,
will@...nel.org, steve.capper@....com,
linux-arm-kernel@...ts.infradead.org, maz@...nel.org,
james.morse@....com, vladimir.murzin@....com, mark.rutland@....com,
tglx@...utronix.de, gregkh@...uxfoundation.org,
allison@...utok.net, info@...ux.net, alexios.zavras@...el.com,
sstabellini@...nel.org, boris.ostrovsky@...cle.com,
jgross@...e.com, stefan@...er.ch, yamada.masahiro@...ionext.com,
xen-devel@...ts.xenproject.org, linux@...linux.org.uk,
andrew.cooper3@...rix.com, julien@....org
Subject: [PATCH v5 2/6] arm/arm64/xen: use C inlines for privcmd_call
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@...een.com>
Acked-by: Stefano Stabellini <sstabellini@...nel.org>
Reviewed-by: Julien Grall <julien@....org>
---
arch/arm/include/asm/xen/hypercall.h | 6 ++++++
arch/arm/xen/enlighten.c | 2 +-
arch/arm/xen/hypercall.S | 4 ++--
arch/arm64/include/asm/xen/hypercall.h | 24 ++++++++++++++++++++++++
arch/arm64/xen/hypercall.S | 19 ++-----------------
include/xen/arm/hypercall.h | 6 +++---
6 files changed, 38 insertions(+), 23 deletions(-)
diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h
index c6882bba5284..cac5bd9ef519 100644
--- a/arch/arm/include/asm/xen/hypercall.h
+++ b/arch/arm/include/asm/xen/hypercall.h
@@ -2,4 +2,10 @@
#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 c3198f9ccd2e..1a74fb28607f 100644
--- a/arch/arm64/include/asm/xen/hypercall.h
+++ b/arch/arm64/include/asm/xen/hypercall.h
@@ -1,5 +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 babcc08af965..624c8ad7e42a 100644
--- a/include/xen/arm/hypercall.h
+++ b/include/xen/arm/hypercall.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);
--
2.17.1
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