KVM: MIPS: Fix VPN2_MASK definition for variable cpu_vmbits

If a CPU support more than 32bit vmbits (which is true for 64bit CPUs),
VPN2_MASK set to fixed 0xffffe000 will lead to a wrong EntryHi in some
functions such as _kvm_mips_host_tlb_inv().

The cpu_vmbits definition of 32bit CPU in cpu-features.h is 31, so we
still use the old definition.

Cc: Stable <stable@vger.kernel.org>
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Signed-off-by: Xing Li <lixing@loongson.cn>
[Huacai: Improve commit messages]
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Message-Id: <1590220602-3547-3-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/mips/include/asm/kvm_host.h

@@ -276,7 +276,11 @@ enum emulation_result {
 #define MIPS3_PG_SHIFT		6
 #define MIPS3_PG_FRAME		0x3fffffc0
 
+#if defined(CONFIG_64BIT)
+#define VPN2_MASK		GENMASK(cpu_vmbits - 1, 13)
+#else
 #define VPN2_MASK		0xffffe000
+#endif
 #define KVM_ENTRYHI_ASID	cpu_asid_mask(&boot_cpu_data)
 #define TLB_IS_GLOBAL(x)	((x).tlb_lo[0] & (x).tlb_lo[1] & ENTRYLO_G)
 #define TLB_VPN2(x)		((x).tlb_hi & VPN2_MASK)