KVM: PPC: Book3S: Controls for in-kernel sPAPR hypercall handling
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 <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
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 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 <asm/processor.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
+#include <asm/hvcall.h>
#define KVM_MAX_VCPUS NR_CPUS
#define KVM_MAX_VCORES NR_CPUS
@@ -263,6 +264,7 @@
#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 @@
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 @@
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 @@
*/
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 @@
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 @@
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 @@
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 @@
{
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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;