Commit 9becbc2e authored by Bibo Mao's avatar Bibo Mao Committed by Xianglai Li
Browse files

LoongArch: KVM: Set reserved bits as zero in CPUCFG 

mainline inclusion
from mainline-v6.9-rc1
commit aebd3bd586c67a29ddbe7be7db06b45754477b52
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9BTOX


CVE: NA

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

Supported CPUCFG information comes from function _kvm_get_cpucfg_mask().
A bit should be zero if it is reserved by HW or if it is not supported
by KVM.

Also LoongArch software page table walk feature defined in CPUCFG2_LSPW
is supported by KVM, it should be enabled by default.

Signed-off-by: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 5f1db44e

arch/loongarch/kvm/vcpu.c

+26 −7
Original line number Diff line number Diff line
@@ -304,11 +304,18 @@ static int _kvm_get_cpucfg_mask(int id, u64 *v) 
		return -EINVAL;



	switch (id) {

	case 2:

	case LOONGARCH_CPUCFG0:

		*v = GENMASK(31, 0);

		return 0;

	case LOONGARCH_CPUCFG1:

		/* CPUCFG1_MSGINT is not supported by KVM */

		*v = GENMASK(25, 0);

		return 0;

	case LOONGARCH_CPUCFG2:

		/* CPUCFG2 features unconditionally supported by KVM */

		*v = CPUCFG2_FP     | CPUCFG2_FPSP  | CPUCFG2_FPDP     |

		     CPUCFG2_FPVERS | CPUCFG2_LLFTP | CPUCFG2_LLFTPREV |

		     CPUCFG2_LAM;

		     CPUCFG2_LSPW | CPUCFG2_LAM;

		/*

		 * For the ISA extensions listed below, if one is supported

		 * by the host, then it is also supported by KVM.
@@ -318,14 +325,26 @@ static int _kvm_get_cpucfg_mask(int id, u64 *v) 
		if (cpu_has_lasx)

			*v |= CPUCFG2_LASX;



		return 0;

	case LOONGARCH_CPUCFG3:

		*v = GENMASK(16, 0);

		return 0;

	case LOONGARCH_CPUCFG4:

	case LOONGARCH_CPUCFG5:

		*v = GENMASK(31, 0);

		return 0;

	case LOONGARCH_CPUCFG16:

		*v = GENMASK(16, 0);

		return 0;

	case LOONGARCH_CPUCFG17 ... LOONGARCH_CPUCFG20:

		*v = GENMASK(30, 0);

		return 0;

	default:

		/*

		 * No restrictions on other valid CPUCFG IDs' values, but

		 * CPUCFG data is limited to 32 bits as the LoongArch ISA

		 * manual says (Volume 1, Section 2.2.10.5 "CPUCFG").

		 * CPUCFG bits should be zero if reserved by HW or not

		 * supported by KVM.

		 */

		*v = U32_MAX;

		*v = 0;

		return 0;

	}

}
@@ -344,7 +363,7 @@ static int kvm_check_cpucfg(int id, u64 val) 
		return -EINVAL;



	switch (id) {

	case 2:

	case LOONGARCH_CPUCFG2:

		if (!(val & CPUCFG2_LLFTP))

			/* Guests must have a constant timer */

			return -EINVAL;