[PATCHv2 2/2] Documentation/kvm/arm: improve description of HVC_SOFT_RESTART

[PATCHv2 2/2] Documentation/kvm/arm: improve description of HVC_SOFT_RESTART

[Pingfan Liu]

Besides disabling MMU, HVC_SOFT_RESTART also clears I+D bits. These behaviors
are what kexec-reboot expects, so describe it more precisely.

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-doc@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
To: linux-arm-kernel@lists.infradead.org
---
 Documentation/virt/kvm/arm/hyp-abi.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/virt/kvm/arm/hyp-abi.rst b/Documentation/virt/kvm/arm/hyp-abi.rst
index d9eba93..83cadd8 100644
--- a/Documentation/virt/kvm/arm/hyp-abi.rst
+++ b/Documentation/virt/kvm/arm/hyp-abi.rst
@@ -54,9 +54,9 @@ these functions (see arch/arm{,64}/include/asm/virt.h):
     x3 = x1's value when entering the next payload (arm64)
     x4 = x2's value when entering the next payload (arm64)
 
-  Mask all exceptions, disable the MMU, move the arguments into place
-  (arm64 only), and jump to the restart address while at HYP/EL2. This
-  hypercall is not expected to return to its caller.
+  Mask all exceptions, disable the MMU, clear I+D bits, move the arguments
+  into place (arm64 only), and jump to the restart address while at HYP/EL2.
+  This hypercall is not expected to return to its caller.
 
 Any other value of r0/x0 triggers a hypervisor-specific handling,
 which is not documented here.
-- 
2.7.5

Re: [PATCHv2 2/2] Documentation/kvm/arm: improve description of HVC_SOFT_RESTART

[Will Deacon]

On Fri, 28 Aug 2020 21:39:58 +0800, Pingfan Liu wrote:
> Besides disabling MMU, HVC_SOFT_RESTART also clears I+D bits. These behaviors
> are what kexec-reboot expects, so describe it more precisely.

Applied to arm64 (for-next/boot), thanks!

[1/1] Documentation/kvm/arm: improve description of HVC_SOFT_RESTART
      https://git.kernel.org/arm64/c/3a1793066fdf

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev