From: Paul Mackerras Date: Mon, 2 Jun 2014 11:02:59 +1000 Subject: KVM: PPC: Book3S: Controls for in-kernel sPAPR hypercall handling Origin: https://git.kernel.org/linus/699a0ea0823d32030b0666b28ff8633960f7ffa7 This provides a way for userspace controls which sPAPR hcalls get handled in the kernel. Each hcall can be individually enabled or disabled for in-kernel handling, except for H_RTAS. The exception for H_RTAS is because userspace can already control whether individual RTAS functions are handled in-kernel or not via the KVM_PPC_RTAS_DEFINE_TOKEN ioctl, and because the numeric value for H_RTAS is out of the normal sequence of hcall numbers. Hcalls are enabled or disabled using the KVM_ENABLE_CAP ioctl for the KVM_CAP_PPC_ENABLE_HCALL capability on the file descriptor for the VM. The args field of the struct kvm_enable_cap specifies the hcall number in args[0] and the enable/disable flag in args[1]; 0 means disable in-kernel handling (so that the hcall will always cause an exit to userspace) and 1 means enable. Enabling or disabling in-kernel handling of an hcall is effective across the whole VM. The ability for KVM_ENABLE_CAP to be used on a VM file descriptor on PowerPC is new, added by this commit. The KVM_CAP_ENABLE_CAP_VM capability advertises that this ability exists. When a VM is created, an initial set of hcalls are enabled for in-kernel handling. The set that is enabled is the set that have an in-kernel implementation at this point. Any new hcall implementations from this point onwards should not be added to the default set without a good reason. No distinction is made between real-mode and virtual-mode hcall implementations; the one setting controls them both. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- Documentation/virtual/kvm/api.txt | 41 +++++++++++++++++++++++-- arch/powerpc/include/asm/kvm_book3s.h | 1 + arch/powerpc/include/asm/kvm_host.h | 2 ++ arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kvm/book3s_hv.c | 51 +++++++++++++++++++++++++++++++ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 +++++++ arch/powerpc/kvm/book3s_pr.c | 5 +++ arch/powerpc/kvm/book3s_pr_papr.c | 37 ++++++++++++++++++++++ arch/powerpc/kvm/powerpc.c | 45 +++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 1 + 10 files changed, 193 insertions(+), 2 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 0fe3649..5c54d19 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2863,8 +2863,8 @@ The fields in each entry are defined as follows: this function/index combination -6. Capabilities that can be enabled ------------------------------------ +6. Capabilities that can be enabled on vCPUs +-------------------------------------------- There are certain capabilities that change the behavior of the virtual CPU when enabled. To enable them, please see section 4.37. Below you can find a list of @@ -3002,3 +3002,40 @@ Parameters: args[0] is the XICS device fd args[1] is the XICS CPU number (server ID) for this vcpu This capability connects the vcpu to an in-kernel XICS device. + + +7. Capabilities that can be enabled on VMs +------------------------------------------ + +There are certain capabilities that change the behavior of the virtual +machine when enabled. To enable them, please see section 4.37. Below +you can find a list of capabilities and what their effect on the VM +is when enabling them. + +The following information is provided along with the description: + + Architectures: which instruction set architectures provide this ioctl. + x86 includes both i386 and x86_64. + + Parameters: what parameters are accepted by the capability. + + Returns: the return value. General error numbers (EBADF, ENOMEM, EINVAL) + are not detailed, but errors with specific meanings are. + + +7.1 KVM_CAP_PPC_ENABLE_HCALL + +Architectures: ppc +Parameters: args[0] is the sPAPR hcall number + args[1] is 0 to disable, 1 to enable in-kernel handling + +This capability controls whether individual sPAPR hypercalls (hcalls) +get handled by the kernel or not. Enabling or disabling in-kernel +handling of an hcall is effective across the VM. On creation, an +initial set of hcalls are enabled for in-kernel handling, which +consists of those hcalls for which in-kernel handlers were implemented +before this capability was implemented. If disabled, the kernel will +not to attempt to handle the hcall, but will always exit to userspace +to handle it. Note that it may not make sense to enable some and +disable others of a group of related hcalls, but KVM does not prevent +userspace from doing that. diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index a20cc0b..052ab2a 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -187,6 +187,7 @@ extern void kvmppc_hv_entry_trampoline(void); extern u32 kvmppc_alignment_dsisr(struct kvm_vcpu *vcpu, unsigned int inst); extern ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst); extern int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd); +extern void kvmppc_pr_init_default_hcalls(struct kvm *kvm); extern void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu, struct kvm_vcpu *vcpu); extern void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu, diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index f9ae696..62b2cee 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -34,6 +34,7 @@ #include #include #include +#include #define KVM_MAX_VCPUS NR_CPUS #define KVM_MAX_VCORES NR_CPUS @@ -263,6 +264,7 @@ struct kvm_arch { #ifdef CONFIG_PPC_BOOK3S_64 struct list_head spapr_tce_tables; struct list_head rtas_tokens; + DECLARE_BITMAP(enabled_hcalls, MAX_HCALL_OPCODE/4 + 1); #endif #ifdef CONFIG_KVM_MPIC struct openpic *mpic; diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index f5995a9..17ffcb4 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -493,6 +493,7 @@ int main(void) DEFINE(KVM_HOST_SDR1, offsetof(struct kvm, arch.host_sdr1)); DEFINE(KVM_TLBIE_LOCK, offsetof(struct kvm, arch.tlbie_lock)); DEFINE(KVM_NEED_FLUSH, offsetof(struct kvm, arch.need_tlb_flush.bits)); + DEFINE(KVM_ENABLED_HCALLS, offsetof(struct kvm, arch.enabled_hcalls)); DEFINE(KVM_LPCR, offsetof(struct kvm, arch.lpcr)); DEFINE(KVM_RMOR, offsetof(struct kvm, arch.rmor)); DEFINE(KVM_VRMA_SLB_V, offsetof(struct kvm, arch.vrma_slb_v)); diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 1562acf..cf445d2 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -67,6 +67,8 @@ /* Used as a "null" value for timebase values */ #define TB_NIL (~(u64)0) +static DECLARE_BITMAP(default_enabled_hcalls, MAX_HCALL_OPCODE/4 + 1); + static void kvmppc_end_cede(struct kvm_vcpu *vcpu); static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu); @@ -562,6 +564,10 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) struct kvm_vcpu *tvcpu; int idx, rc; + if (req <= MAX_HCALL_OPCODE && + !test_bit(req/4, vcpu->kvm->arch.enabled_hcalls)) + return RESUME_HOST; + switch (req) { case H_ENTER: idx = srcu_read_lock(&vcpu->kvm->srcu); @@ -2269,6 +2275,10 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm) */ cpumask_setall(&kvm->arch.need_tlb_flush); + /* Start out with the default set of hcalls enabled */ + memcpy(kvm->arch.enabled_hcalls, default_enabled_hcalls, + sizeof(kvm->arch.enabled_hcalls)); + kvm->arch.rma = NULL; kvm->arch.host_sdr1 = mfspr(SPRN_SDR1); @@ -2407,6 +2417,45 @@ static long kvm_arch_vm_ioctl_hv(struct file *filp, return r; } +/* + * List of hcall numbers to enable by default. + * For compatibility with old userspace, we enable by default + * all hcalls that were implemented before the hcall-enabling + * facility was added. Note this list should not include H_RTAS. + */ +static unsigned int default_hcall_list[] = { + H_REMOVE, + H_ENTER, + H_READ, + H_PROTECT, + H_BULK_REMOVE, + H_GET_TCE, + H_PUT_TCE, + H_SET_DABR, + H_SET_XDABR, + H_CEDE, + H_PROD, + H_CONFER, + H_REGISTER_VPA, +#ifdef CONFIG_KVM_XICS + H_EOI, + H_CPPR, + H_IPI, + H_IPOLL, + H_XIRR, + H_XIRR_X, +#endif + 0 +}; + +static void init_default_hcalls(void) +{ + int i; + + for (i = 0; default_hcall_list[i]; ++i) + __set_bit(default_hcall_list[i] / 4, default_enabled_hcalls); +} + static struct kvmppc_ops kvm_ops_hv = { .get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv, .set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv, @@ -2454,6 +2503,8 @@ static int kvmppc_book3s_init_hv(void) kvm_ops_hv.owner = THIS_MODULE; kvmppc_hv_ops = &kvm_ops_hv; + init_default_hcalls(); + r = kvmppc_mmu_hv_init(); return r; } diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 64ac56f..33aaade 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1909,6 +1909,17 @@ hcall_try_real_mode: clrrdi r3,r3,2 cmpldi r3,hcall_real_table_end - hcall_real_table bge guest_exit_cont + /* See if this hcall is enabled for in-kernel handling */ + ld r4, VCPU_KVM(r9) + srdi r0, r3, 8 /* r0 = (r3 / 4) >> 6 */ + sldi r0, r0, 3 /* index into kvm->arch.enabled_hcalls[] */ + add r4, r4, r0 + ld r0, KVM_ENABLED_HCALLS(r4) + rlwinm r4, r3, 32-2, 0x3f /* r4 = (r3 / 4) & 0x3f */ + srd r0, r0, r4 + andi. r0, r0, 1 + beq guest_exit_cont + /* Get pointer to handler, if any, and call it */ LOAD_REG_ADDR(r4, hcall_real_table) lwax r3,r3,r4 cmpwi r3,0 diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 3b82e86..123ac7d 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1597,6 +1597,11 @@ static int kvmppc_core_init_vm_pr(struct kvm *kvm) { mutex_init(&kvm->arch.hpt_mutex); +#ifdef CONFIG_PPC_BOOK3S_64 + /* Start out with the default set of hcalls enabled */ + kvmppc_pr_init_default_hcalls(kvm); +#endif + if (firmware_has_feature(FW_FEATURE_SET_MODE)) { spin_lock(&kvm_global_user_count_lock); if (++kvm_global_user_count == 1) diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c index f7c25c6..eacaa6e 100644 --- a/arch/powerpc/kvm/book3s_pr_papr.c +++ b/arch/powerpc/kvm/book3s_pr_papr.c @@ -267,6 +267,10 @@ static int kvmppc_h_pr_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd) int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd) { + if (cmd <= MAX_HCALL_OPCODE && + !test_bit(cmd/4, vcpu->kvm->arch.enabled_hcalls)) + return EMULATE_FAIL; + switch (cmd) { case H_ENTER: return kvmppc_h_pr_enter(vcpu); @@ -304,3 +308,36 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd) return EMULATE_FAIL; } + + +/* + * List of hcall numbers to enable by default. + * For compatibility with old userspace, we enable by default + * all hcalls that were implemented before the hcall-enabling + * facility was added. Note this list should not include H_RTAS. + */ +static unsigned int default_hcall_list[] = { + H_ENTER, + H_REMOVE, + H_PROTECT, + H_BULK_REMOVE, + H_PUT_TCE, + H_CEDE, +#ifdef CONFIG_KVM_XICS + H_XIRR, + H_CPPR, + H_EOI, + H_IPI, + H_IPOLL, + H_XIRR_X, +#endif + 0 +}; + +void kvmppc_pr_init_default_hcalls(struct kvm *kvm) +{ + int i; + + for (i = 0; default_hcall_list[i]; ++i) + __set_bit(default_hcall_list[i] / 4, kvm->arch.enabled_hcalls); +} diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 61c738a..3222a4d 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -387,6 +387,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_PPC_UNSET_IRQ: case KVM_CAP_PPC_IRQ_LEVEL: case KVM_CAP_ENABLE_CAP: + case KVM_CAP_ENABLE_CAP_VM: case KVM_CAP_ONE_REG: case KVM_CAP_IOEVENTFD: case KVM_CAP_DEVICE_CTRL: @@ -417,6 +418,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_PPC_ALLOC_HTAB: case KVM_CAP_PPC_RTAS: case KVM_CAP_PPC_FIXUP_HCALL: + case KVM_CAP_PPC_ENABLE_HCALL: #ifdef CONFIG_KVM_XICS case KVM_CAP_IRQ_XICS: #endif @@ -1099,6 +1101,40 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_event, return 0; } + +static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, + struct kvm_enable_cap *cap) +{ + int r; + + if (cap->flags) + return -EINVAL; + + switch (cap->cap) { +#ifdef CONFIG_KVM_BOOK3S_64_HANDLER + case KVM_CAP_PPC_ENABLE_HCALL: { + unsigned long hcall = cap->args[0]; + + r = -EINVAL; + if (hcall > MAX_HCALL_OPCODE || (hcall & 3) || + cap->args[1] > 1) + break; + if (cap->args[1]) + set_bit(hcall / 4, kvm->arch.enabled_hcalls); + else + clear_bit(hcall / 4, kvm->arch.enabled_hcalls); + r = 0; + break; + } +#endif + default: + r = -EINVAL; + break; + } + + return r; +} + long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -1118,6 +1154,15 @@ long kvm_arch_vm_ioctl(struct file *filp, break; } + case KVM_ENABLE_CAP: + { + struct kvm_enable_cap cap; + r = -EFAULT; + if (copy_from_user(&cap, argp, sizeof(cap))) + goto out; + r = kvm_vm_ioctl_enable_cap(kvm, &cap); + break; + } #ifdef CONFIG_PPC_BOOK3S_64 case KVM_CREATE_SPAPR_TCE: { struct kvm_create_spapr_tce create_tce; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index e11d8f1..0418b74 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -758,6 +758,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_VM_ATTRIBUTES 101 #define KVM_CAP_ARM_PSCI_0_2 102 #define KVM_CAP_PPC_FIXUP_HCALL 103 +#define KVM_CAP_PPC_ENABLE_HCALL 104 #ifdef KVM_CAP_IRQ_ROUTING -- 1.7.10.4