diff options
author | Mark Rutland <mark.rutland@arm.com> | 2017-02-20 12:30:12 +0000 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-14 09:28:19 +0100 |
commit | aafb72d2ed5579208191cfc3fb9425570c1303ce (patch) | |
tree | bc2d3f8d12e1302beba37c6bed5053a4bca527a4 /virt | |
parent | 5e366aaec185c83157a126dad227a75e59899c62 (diff) |
arm64: KVM: Survive unknown traps from guests
[ Upstream commit ba4dd156eabdca93501d92a980ba27fa5f4bbd27 ]
Currently we BUG() if we see an ESR_EL2.EC value we don't recognise. As
configurable disables/enables are added to the architecture (controlled
by RES1/RES0 bits respectively), with associated synchronous exceptions,
it may be possible for a guest to trigger exceptions with classes that
we don't recognise.
While we can't service these exceptions in a manner useful to the guest,
we can avoid bringing down the host. Per ARM DDI 0487A.k_iss10775, page
D7-1937, EC values within the range 0x00 - 0x2c are reserved for future
use with synchronous exceptions, and EC values within the range 0x2d -
0x3f may be used for either synchronous or asynchronous exceptions.
The patch makes KVM handle any unknown EC by injecting an UNDEFINED
exception into the guest, with a corresponding (ratelimited) warning in
the host dmesg. We could later improve on this with with a new (opt-in)
exit to the host userspace.
Cc: Dave Martin <dave.martin@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions