This provides a way for userspace controls which PAPR 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. 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, even though the KVM_ENABLE_CAP ioctl is
applied to a vcpu.
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.
No distinction is made between real-mode and virtual-mode hcall
implementations; the one setting controls them both.
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
---
Documentation/virtual/kvm/api.txt | 17 +++++++++++
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 | 19 ++++++++++++
include/uapi/linux/kvm.h | 1 +
10 files changed, 145 insertions(+)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 6b0225d..dfd6e0c 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2983,3 +2983,20 @@ 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.
+
+6.8 KVM_CAP_PPC_ENABLE_HCALL
+
+Architectures: ppc
+Parameters: args[0] is the PAPR hcall number
+ args[1] is 0 to disable, 1 to enable in-kernel handling
+
+This capability controls whether individual PAPR 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 will 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 f52f656..772044b 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -189,6 +189,7 @@ 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 bb66d8b..2889587 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 @@ 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 93e1465..c427b51 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -492,6 +492,7 @@ 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 aba05bb..84e695d 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);
@@ -2275,6 +2281,10 @@ 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);
@@ -2413,6 +2423,45 @@ 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,
@@ -2460,6 +2509,8 @@ 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 220aefb..c26b0e2 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1795,6 +1795,17 @@ 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 23367a7..59dc94e 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -1568,6 +1568,11 @@ 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 52a63bf..c5afde2 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -266,6 +266,10 @@ 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);
@@ -303,3 +307,36 @@ 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 154f352..5690c74 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -416,6 +416,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_SPAPR_TCE:
case KVM_CAP_PPC_ALLOC_HTAB:
case KVM_CAP_PPC_RTAS:
+ case KVM_CAP_PPC_ENABLE_HCALL:
#ifdef CONFIG_KVM_XICS
case KVM_CAP_IRQ_XICS:
#endif
@@ -964,6 +965,24 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
break;
}
#endif /* CONFIG_KVM_XICS */
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
+ case KVM_CAP_PPC_ENABLE_HCALL: {
+ unsigned long hcall = cap->args[0];
+
+ r = -EINVAL;
+ if (!vcpu->arch.papr_enabled)
+ break;
+ if (hcall > MAX_HCALL_OPCODE || (hcall & 3) ||
+ cap->args[1] > 1)
+ break;
+ if (cap->args[1])
+ set_bit(hcall / 4, vcpu->kvm->arch.enabled_hcalls);
+ else
+ clear_bit(hcall / 4, vcpu->kvm->arch.enabled_hcalls);
+ r = 0;
+ break;
+ }
+#endif
default:
r = -EINVAL;
break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 836e15b..79e4532 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -746,6 +746,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_S390_IRQCHIP 99
#define KVM_CAP_IOEVENTFD_NO_LENGTH 100
#define KVM_CAP_VM_ATTRIBUTES 101
+#define KVM_CAP_PPC_ENABLE_HCALL 102
#ifdef KVM_CAP_IRQ_ROUTING
--
2.0.0.rc2
--
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