From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH] arm64: kvm: 4.6-rc1: Fix VTCR_EL2 VS setting Date: Wed, 30 Mar 2016 22:09:00 +0200 Message-ID: <20160330200900.GM4126@cbox> References: <1459344839-14397-1-git-send-email-suzuki.poulose@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: marc.zyngier@arm.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org To: Suzuki K Poulose Return-path: Content-Disposition: inline In-Reply-To: <1459344839-14397-1-git-send-email-suzuki.poulose@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org On Wed, Mar 30, 2016 at 02:33:59PM +0100, Suzuki K Poulose wrote: > When we detect support for 16bit VMID in ID_AA64MMFR1, we set the > VTCR_EL2_VS field to 1 to make use of 16bit vmids. But, with > commit 3a3604bc5eb4 ("arm64: KVM: Switch to C-based stage2 init") > this is broken and we corrupt VTCR_EL2:T0SZ instead of updating the VS > field. VTCR_EL2_VS was actually defined to the field shift (19) and > not the real value for VS. This patch fixes the issue. > > Fixes: commit 3a3604bc5eb4 ("arm64: KVM: Switch to C-based stage2 init") > Cc: Christoffer Dall > Cc: Mark Rutland > Acked-by: Marc Zyngier > Signed-off-by: Suzuki K Poulose Acked-by: Christoffer Dall > --- > arch/arm64/include/asm/kvm_arm.h | 4 +++- > arch/arm64/include/asm/sysreg.h | 3 +++ > arch/arm64/kvm/hyp/s2-setup.c | 6 ++++-- > 3 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 0e391db..4150fd8 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -124,7 +124,9 @@ > #define VTCR_EL2_SL0_LVL1 (1 << 6) > #define VTCR_EL2_T0SZ_MASK 0x3f > #define VTCR_EL2_T0SZ_40B 24 > -#define VTCR_EL2_VS 19 > +#define VTCR_EL2_VS_SHIFT 19 > +#define VTCR_EL2_VS_8BIT (0 << VTCR_EL2_VS_SHIFT) > +#define VTCR_EL2_VS_16BIT (1 << VTCR_EL2_VS_SHIFT) > > /* > * We configure the Stage-2 page tables to always restrict the IPA space to be > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index 1a78d6e..1287416 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -141,6 +141,9 @@ > #define ID_AA64MMFR1_VMIDBITS_SHIFT 4 > #define ID_AA64MMFR1_HADBS_SHIFT 0 > > +#define ID_AA64MMFR1_VMIDBITS_8 0 > +#define ID_AA64MMFR1_VMIDBITS_16 2 > + > /* id_aa64mmfr2 */ > #define ID_AA64MMFR2_UAO_SHIFT 4 > > diff --git a/arch/arm64/kvm/hyp/s2-setup.c b/arch/arm64/kvm/hyp/s2-setup.c > index bfc54fd..5a9f3bf 100644 > --- a/arch/arm64/kvm/hyp/s2-setup.c > +++ b/arch/arm64/kvm/hyp/s2-setup.c > @@ -36,8 +36,10 @@ void __hyp_text __init_stage2_translation(void) > * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS > * bit in VTCR_EL2. > */ > - tmp = (read_sysreg(id_aa64mmfr1_el1) >> 4) & 0xf; > - val |= (tmp == 2) ? VTCR_EL2_VS : 0; > + tmp = (read_sysreg(id_aa64mmfr1_el1) >> ID_AA64MMFR1_VMIDBITS_SHIFT) & 0xf; > + val |= (tmp == ID_AA64MMFR1_VMIDBITS_16) ? > + VTCR_EL2_VS_16BIT : > + VTCR_EL2_VS_8BIT; > > write_sysreg(val, vtcr_el2); > } > -- > 1.7.9.5 >