KVM: arm64: Save guest's ZCR_EL1 before saving the FPSIMD state

mainline inclusion
from mainline-v5.13-rc1~76^2
commit b145a843
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ITJT
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b145a8437aab2799969f6ad8e384b557872333c2

-------------------------------------------------

Make sure the guest's ZCR_EL1 is saved before we save/flush the
state. This will be useful in later patches.
Acked-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>

arch/arm64/kvm/fpsimd.c

@@ -121,10 +121,10 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
 	local_irq_save(flags);
 
 	if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
-		fpsimd_save_and_flush_cpu_state();
-
 		if (guest_has_sve)
 			__vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR);
+
+		fpsimd_save_and_flush_cpu_state();
 	} else if (host_has_sve) {
 		/*
 		 * The FPSIMD/SVE state in the CPU has not been touched, and we