[Xen-devel,RFC,for-4.13,01/10] xen/arm64: entry: Introduce a macro to generate guest vector and use it

Message ID 20190926183808.11630-2-julien.grall@arm.com
State Superseded
Headers show
Series
  • xen/arm: XSA-201 and XSA-263 fixes
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Commit Message

Julien Grall Sept. 26, 2019, 6:37 p.m.
Most of the guest vectors are using the same pattern. This makes fairly
tedious to alter the pattern and risk introducing mistakes when updating
each path.

A new macro is introduced to generate the guest vectors and now use it
in the one that use the open-code version.

Signed-off-by: Julien Grall <julien.grall@arm.com>
---
 xen/arch/arm/arm64/entry.S | 84 ++++++++++++++++------------------------------
 1 file changed, 28 insertions(+), 56 deletions(-)

Comments

Volodymyr Babchuk Sept. 27, 2019, 11:34 a.m. | #1
Hello Julien,

Julien Grall writes:

> Most of the guest vectors are using the same pattern. This makes fairly
> tedious to alter the pattern and risk introducing mistakes when updating
> each path.
>
> A new macro is introduced to generate the guest vectors and now use it
> in the one that use the open-code version.
>
> Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Stefano Stabellini Oct. 1, 2019, 7:53 p.m. | #2
On Fri, 27 Sep 2019, Volodymyr Babchuk wrote:
> 
> Hello Julien,
> 
> Julien Grall writes:
> 
> > Most of the guest vectors are using the same pattern. This makes fairly
> > tedious to alter the pattern and risk introducing mistakes when updating
> > each path.
> >
> > A new macro is introduced to generate the guest vectors and now use it
> > in the one that use the open-code version.
> >
> > Signed-off-by: Julien Grall <julien.grall@arm.com>
> Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

Patch

diff --git a/xen/arch/arm/arm64/entry.S b/xen/arch/arm/arm64/entry.S
index 2d9a2713a1..8665d2844a 100644
--- a/xen/arch/arm/arm64/entry.S
+++ b/xen/arch/arm/arm64/entry.S
@@ -157,6 +157,30 @@ 
 
         .endm
 
+        /*
+         * Generate a guest vector.
+         *
+         * iflags: Correspond to the list of interrupts to unmask
+         * save_x0_x1: See the description on top of the macro 'entry'
+         */
+        .macro  guest_vector compat, iflags, trap, save_x0_x1=1
+        entry   hyp=0, compat=\compat, save_x0_x1=\save_x0_x1
+        /*
+         * The vSError will be checked while SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
+         * is not set. If a vSError took place, the initial exception will be
+         * skipped. Exit ASAP
+         */
+        ALTERNATIVE("bl check_pending_vserror; cbnz x0, 1f",
+                    "nop; nop",
+                    SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
+        msr     daifclr, \iflags
+        mov     x0, sp
+        bl      do_trap_\trap
+1:
+        exit    hyp=0, compat=\compat
+        .endm
+
+
 /*
  * Bad Abort numbers
  *-----------------
@@ -290,36 +314,10 @@  guest_sync_slowpath:
          * x0/x1 may have been scratch by the fast path above, so avoid
          * to save them.
          */
-        entry   hyp=0, compat=0, save_x0_x1=0
-        /*
-         * The vSError will be checked while SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
-         * is not set. If a vSError took place, the initial exception will be
-         * skipped. Exit ASAP
-         */
-        ALTERNATIVE("bl check_pending_vserror; cbnz x0, 1f",
-                    "nop; nop",
-                    SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
-        msr     daifclr, #6
-        mov     x0, sp
-        bl      do_trap_guest_sync
-1:
-        exit    hyp=0, compat=0
+        guest_vector compat=0, iflags=6, trap=guest_sync, save_x0_x1=0
 
 guest_irq:
-        entry   hyp=0, compat=0
-        /*
-         * The vSError will be checked while SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
-         * is not set. If a vSError took place, the initial exception will be
-         * skipped. Exit ASAP
-         */
-        ALTERNATIVE("bl check_pending_vserror; cbnz x0, 1f",
-                    "nop; nop",
-                    SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
-        msr     daifclr, #4
-        mov     x0, sp
-        bl      do_trap_irq
-1:
-        exit    hyp=0, compat=0
+        guest_vector compat=0, iflags=4, trap=irq
 
 guest_fiq_invalid:
         entry   hyp=0, compat=0
@@ -333,36 +331,10 @@  guest_error:
         exit    hyp=0, compat=0
 
 guest_sync_compat:
-        entry   hyp=0, compat=1
-        /*
-         * The vSError will be checked while SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
-         * is not set. If a vSError took place, the initial exception will be
-         * skipped. Exit ASAP
-         */
-        ALTERNATIVE("bl check_pending_vserror; cbnz x0, 1f",
-                    "nop; nop",
-                    SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
-        msr     daifclr, #6
-        mov     x0, sp
-        bl      do_trap_guest_sync
-1:
-        exit    hyp=0, compat=1
+        guest_vector compat=1, iflags=6, trap=guest_sync
 
 guest_irq_compat:
-        entry   hyp=0, compat=1
-        /*
-         * The vSError will be checked while SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
-         * is not set. If a vSError took place, the initial exception will be
-         * skipped. Exit ASAP
-         */
-        ALTERNATIVE("bl check_pending_vserror; cbnz x0, 1f",
-                    "nop; nop",
-                    SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
-        msr     daifclr, #4
-        mov     x0, sp
-        bl      do_trap_irq
-1:
-        exit    hyp=0, compat=1
+        guest_vector compat=1, iflags=4, trap=irq
 
 guest_fiq_invalid_compat:
         entry   hyp=0, compat=1