arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
authorDave Martin <Dave.Martin@arm.com>
Thu, 21 Feb 2019 11:42:32 +0000 (11:42 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 23 Mar 2019 13:35:28 +0000 (14:35 +0100)
commit5b8749bd1154c4b3425d2aa6060ebaa21c866603
treecc00152387d79af4f0fd664207a001284bfa9b75
parentd5ed64073c4bc4254c0fe32d2b3d013d45299b89
arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2

commit c88b093693ccbe41991ef2e9b1d251945e6e54ed upstream.

Due to what looks like a typo dating back to the original addition
of FPEXC32_EL2 handling, KVM currently initialises this register to
an architecturally invalid value.

As a result, the VECITR field (RES1) in bits [10:8] is initialised
with 0, and the two reserved (RES0) bits [6:5] are initialised with
1.  (In the Common VFP Subarchitecture as specified by ARMv7-A,
these two bits were IMP DEF.  ARMv8-A removes them.)

This patch changes the reset value from 0x70 to 0x700, which
reflects the architectural constraints and is presumably what was
originally intended.

Cc: <stable@vger.kernel.org> # 4.12.x-
Cc: Christoffer Dall <christoffer.dall@arm.com>
Fixes: 62a89c44954f ("arm64: KVM: 32bit handling of coprocessor traps")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/kvm/sys_regs.c