Hi Jan,
On 17/05/2021 08:01, Jan Beulich wrote:
On 12.05.2021 19:59, Julien Grall wrote:
Hi,
On 11/05/2021 07:37, Michal Orzel wrote:
On 05.05.2021 10:00, Jan Beulich wrote:
On 05.05.2021 09:43, Michal Orzel wrote:
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -267,10 +267,10 @@ struct vcpu_guest_core_regs
/* Return address and mode */
__DECL_REG(pc64, pc32); /* ELR_EL2 */
- uint32_t cpsr; /* SPSR_EL2 */
+ uint64_t cpsr; /* SPSR_EL2 */
union {
- uint32_t spsr_el1; /* AArch64 */
+ uint64_t spsr_el1; /* AArch64 */
uint32_t spsr_svc; /* AArch32 */
};
This change affects, besides domctl, also default_initialise_vcpu(),
which Arm's arch_initialise_vcpu() calls. I realize do_arm_vcpu_op()
only allows two unrelated VCPUOP_* to pass, but then I don't
understand why arch_initialise_vcpu() doesn't simply return e.g.
-EOPNOTSUPP. Hence I suspect I'm missing something.
I think it is just an overlooked when reviewing the following commit:
commit 192df6f9122ddebc21d0a632c10da3453aeee1c2
Author: Roger Pau Monné <roger....@citrix.com>
Date: Tue Dec 15 14:12:32 2015 +0100
x86: allow HVM guests to use hypercalls to bring up vCPUs
Allow the usage of the VCPUOP_initialise, VCPUOP_up, VCPUOP_down,
VCPUOP_is_up, VCPUOP_get_physid and VCPUOP_send_nmi hypercalls from HVM
guests.
This patch introduces a new structure (vcpu_hvm_context) that
should be used
in conjuction with the VCPUOP_initialise hypercall in order to
initialize
vCPUs for HVM guests.
Signed-off-by: Roger Pau Monné <roger....@citrix.com>
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
Acked-by: Ian Campbell <ian.campb...@citrix.com>
On Arm, the structure vcpu_guest_context is not exposed outside of Xen
and the tools. Interestingly vcpu_guest_core_regs is but it should only
be used within vcpu_guest_context.
So as this is not used by stable ABI, it is fine to break it.
I agree that do_arm_vcpu_op only allows two VCPUOP* to pass and
arch_initialise_vcpu being called in case of VCPUOP_initialise
has no sense as VCPUOP_initialise is not supported on arm.
It makes sense that it should return -EOPNOTSUPP.
However do_arm_vcpu_op will not accept VCPUOP_initialise and will return
-EINVAL. So arch_initialise_vcpu for arm will not be called.
Do you think that changing this behaviour so that arch_initialise_vcpu returns
-EOPNOTSUPP should be part of this patch?
I think this change is unrelated. So it should be handled in a follow-up
patch.
My only difference in viewing this is that I'd say the adjustment
would better be a prereq patch to this one, such that the one here
ends up being more obviously correct.
The function is already not reachable so I felt it was unfair to require
the clean-up for merging this code.
Also, if the function is
indeed not meant to be reachable, besides making it return
-EOPNOTSUPP (or alike) it should probably also have
ASSERT_UNREACHABLE() added.
+1 on the idea.
Cheers,
--
Julien Grall
