4.14-stable review patch. If anyone has any objections, please let me know.
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From: Dave Martin Dave.Martin@arm.com
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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1079,7 +1079,7 @@ static const struct sys_reg_desc sys_reg
{ SYS_DESC(SYS_DACR32_EL2), NULL, reset_unknown, DACR32_EL2 }, { SYS_DESC(SYS_IFSR32_EL2), NULL, reset_unknown, IFSR32_EL2 }, - { SYS_DESC(SYS_FPEXC32_EL2), NULL, reset_val, FPEXC32_EL2, 0x70 }, + { SYS_DESC(SYS_FPEXC32_EL2), NULL, reset_val, FPEXC32_EL2, 0x700 }, };
static bool trap_dbgidr(struct kvm_vcpu *vcpu,