| Message ID | 1500397144-16232-37-git-send-email-jintack.lim@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 18, 2017 at 11:59:02AM -0500, Jintack Lim wrote: > 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. I noticed that all these recursive patches don't change how we program the physical HCR_EL2. Is that because we always respect the guest hypervisor's configuration of the virtual HCR_EL2 into the physical one when running the VM? If so, perhaps we should add a single sentence in the commit messages about that. > > This is for recursive nested virtualization. > > Signed-off-by: Jintack Lim <jintack.lim@linaro.org> > --- > 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 */ it's just 'recursive nested virtualization', not 'the recursive nested virtualization', and I also think 'recursive virtualization' is sufficient. > +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)); why do you need the !el12_reg(p) check here? > + > /* > * Redirect EL1 register accesses to the corresponding EL2 registers if > * they are meant to access EL2 registers. > -- > 1.9.1 > Thanks, -Christoffer
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.
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 <jintack.lim@linaro.org> --- arch/arm64/kvm/sys_regs.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)