From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jintack Lim Subject: [RFC PATCH v2 36/38] KVM: arm64: Respect virtual HCR_EL2.TVM and TRVM settings Date: Tue, 18 Jul 2017 11:59:02 -0500 Message-ID: <1500397144-16232-37-git-send-email-jintack.lim@linaro.org> References: <1500397144-16232-1-git-send-email-jintack.lim@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, david.daney@cavium.com, catalin.marinas@arm.com, will.deacon@arm.com, stefan@hello-penguin.com, corbet@lwn.net, daniel.lezcano@linaro.org, linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, andy.gross@linaro.org, cov@codeaurora.org, wcohen@redhat.com, mchehab@kernel.org, ard.biesheuvel@linaro.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, akpm@linux-foundation.org To: kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org, marc.zyngier@arm.com Return-path: In-Reply-To: <1500397144-16232-1-git-send-email-jintack.lim@linaro.org> 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 Forward the EL1 virtual memory register traps to the virtual EL2 if they are not coming from the virtual EL2 and the virtual HCR_EL2.TVM or TRVM bit is set. This is for recursive nested virtualization. Signed-off-by: Jintack Lim --- arch/arm64/kvm/sys_regs.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 3559cf7..3e4ec5e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -135,6 +135,27 @@ static inline bool el12_reg(struct sys_reg_params *p) return (p->Op1 == 5); } +/* This function is to support the recursive nested virtualization */ +static bool forward_vm_traps(struct kvm_vcpu *vcpu, struct sys_reg_params *p) +{ + u64 hcr_el2 = vcpu_sys_reg(vcpu, HCR_EL2); + + /* If a trap comes from the virtual EL2, the host hypervisor handles. */ + if (vcpu_mode_el2(vcpu)) + return false; + + /* + * If the virtual HCR_EL2.TVM or TRVM bit is set, we need to foward + * this trap to the virtual EL2. + */ + if ((hcr_el2 & HCR_TVM) && p->is_write) + return true; + else if ((hcr_el2 & HCR_TRVM) && !p->is_write) + return true; + + return false; +} + /* * Generic accessor for VM registers. Only called as long as HCR_TVM * is set. If the guest enables the MMU, we stop trapping the VM @@ -152,6 +173,9 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu, if (el12_reg(p) && forward_nv_traps(vcpu)) return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + if (!el12_reg(p) && forward_vm_traps(vcpu, p)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + /* * Redirect EL1 register accesses to the corresponding EL2 registers if * they are meant to access EL2 registers. -- 1.9.1