Export kernel paravirt features to user space, so that VMM can control
the single paravirt feature. By default paravirt features will the same
with kvm supported features if VMM does not set it.
Also a new feature KVM_FEATURE_VIRT_EXTIOI is added which can be set from
user space. This feature indicates that the virt EXTIOI can route
interrupts to 256 vCPUs, rather than 4 vCPUs like with real HW.
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
---
arch/loongarch/include/asm/kvm_host.h | 9 +++++
arch/loongarch/include/asm/kvm_para.h | 1 +
arch/loongarch/include/asm/loongarch.h | 13 -------
arch/loongarch/include/uapi/asm/Kbuild | 2 --
arch/loongarch/include/uapi/asm/kvm.h | 2 ++
arch/loongarch/include/uapi/asm/kvm_para.h | 24 +++++++++++++
arch/loongarch/kvm/exit.c | 4 +--
arch/loongarch/kvm/vcpu.c | 41 +++++++++++++++++++---
arch/loongarch/kvm/vm.c | 12 +++++++
9 files changed, 86 insertions(+), 22 deletions(-)
create mode 100644 arch/loongarch/include/uapi/asm/kvm_para.h
diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
index c409ab15bae1..82d2c62416a7 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -109,6 +109,10 @@ struct kvm_arch {
unsigned int root_level;
spinlock_t phyid_map_lock;
struct kvm_phyid_map *phyid_map;
+ /* Supported PV features */
+ unsigned long pv_capability;
+ /* Enabled PV features */
+ unsigned long pv_features;
s64 time_offset;
struct kvm_context __percpu *vmcs;
@@ -139,6 +143,11 @@ enum emulation_result {
#define KVM_LARCH_HWCSR_USABLE (0x1 << 4)
#define KVM_LARCH_LBT (0x1 << 5)
+#define LOONGARCH_PV_FEAT_UPDATED BIT_ULL(63)
+#define LOONGARCH_PV_FEAT_MASK \
+ (KVM_FEATURE_IPI | KVM_FEATURE_STEAL_TIME | \
+ KVM_FEATURE_VIRT_EXTIOI)
+
struct kvm_vcpu_arch {
/*
* Switch pointer-to-function type to unsigned long
diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h
index 335fb86778e2..9814d56b8d0e 100644
--- a/arch/loongarch/include/asm/kvm_para.h
+++ b/arch/loongarch/include/asm/kvm_para.h
@@ -2,6 +2,7 @@
#ifndef _ASM_LOONGARCH_KVM_PARA_H
#define _ASM_LOONGARCH_KVM_PARA_H
+#include <uapi/asm/kvm_para.h>
/*
* Hypercall code field
*/
diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h
index 04a78010fc72..eb82230f52c3 100644
--- a/arch/loongarch/include/asm/loongarch.h
+++ b/arch/loongarch/include/asm/loongarch.h
@@ -158,19 +158,6 @@
#define CPUCFG48_VFPU_CG BIT(2)
#define CPUCFG48_RAM_CG BIT(3)
-/*
- * CPUCFG index area: 0x40000000 -- 0x400000ff
- * SW emulation for KVM hypervirsor
- */
-#define CPUCFG_KVM_BASE 0x40000000
-#define CPUCFG_KVM_SIZE 0x100
-
-#define CPUCFG_KVM_SIG (CPUCFG_KVM_BASE + 0)
-#define KVM_SIGNATURE "KVM\0"
-#define CPUCFG_KVM_FEATURE (CPUCFG_KVM_BASE + 4)
-#define KVM_FEATURE_IPI BIT(1)
-#define KVM_FEATURE_STEAL_TIME BIT(2)
-
#ifndef __ASSEMBLY__
/* CSR */
diff --git a/arch/loongarch/include/uapi/asm/Kbuild b/arch/loongarch/include/uapi/asm/Kbuild
index c6d141d7b7d7..517761419999 100644
--- a/arch/loongarch/include/uapi/asm/Kbuild
+++ b/arch/loongarch/include/uapi/asm/Kbuild
@@ -1,4 +1,2 @@
# SPDX-License-Identifier: GPL-2.0
syscall-y += unistd_64.h
-
-generic-y += kvm_para.h
diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h
index 003fb766c93f..4d56ec3777a0 100644
--- a/arch/loongarch/include/uapi/asm/kvm.h
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -98,6 +98,8 @@ struct kvm_fpu {
#define KVM_LOONGARCH_VM_FEAT_X86BT 2
#define KVM_LOONGARCH_VM_FEAT_ARMBT 3
#define KVM_LOONGARCH_VM_FEAT_MIPSBT 4
+#define KVM_LOONGARCH_VM_FEAT_PV_IPI 5
+#define KVM_LOONGARCH_VM_FEAT_PV_STEALTIME 6
/* Device Control API on vcpu fd */
#define KVM_LOONGARCH_VCPU_CPUCFG 0
diff --git a/arch/loongarch/include/uapi/asm/kvm_para.h b/arch/loongarch/include/uapi/asm/kvm_para.h
new file mode 100644
index 000000000000..a63b67c90240
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/kvm_para.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _UAPI_ASM_LOONGARCH_KVM_PARA_H
+#define _UAPI_ASM_LOONGARCH_KVM_PARA_H
+
+#include <linux/types.h>
+
+/*
+ * CPUCFG index area: 0x40000000 -- 0x400000ff
+ * SW emulation for KVM hypervirsor
+ */
+#define CPUCFG_KVM_BASE 0x40000000
+#define CPUCFG_KVM_SIZE 0x100
+#define CPUCFG_KVM_SIG (CPUCFG_KVM_BASE + 0)
+#define KVM_SIGNATURE "KVM\0"
+#define CPUCFG_KVM_FEATURE (CPUCFG_KVM_BASE + 4)
+#define KVM_FEATURE_IPI BIT(1)
+#define KVM_FEATURE_STEAL_TIME BIT(2)
+/*
+ * BIT 24 - 31 is features configurable by user space vmm
+ * With VIRT_EXTIOI feature, interrupt can route to 256 VCPUs
+ */
+#define KVM_FEATURE_VIRT_EXTIOI BIT(24)
+
+#endif /* _UAPI_ASM_LOONGARCH_KVM_PARA_H */
diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
index be2c326253a3..e293b95f456a 100644
--- a/arch/loongarch/kvm/exit.c
+++ b/arch/loongarch/kvm/exit.c
@@ -50,9 +50,7 @@ static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst)
vcpu->arch.gprs[rd] = *(unsigned int *)KVM_SIGNATURE;
break;
case CPUCFG_KVM_FEATURE:
- ret = KVM_FEATURE_IPI;
- if (kvm_pvtime_supported())
- ret |= KVM_FEATURE_STEAL_TIME;
+ ret = vcpu->kvm->arch.pv_features & LOONGARCH_PV_FEAT_MASK;
vcpu->arch.gprs[rd] = ret;
break;
default:
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index b8210442c178..4918bebdf666 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -793,6 +793,8 @@ static int kvm_loongarch_cpucfg_has_attr(struct kvm_vcpu *vcpu,
switch (attr->attr) {
case 2:
return 0;
+ case CPUCFG_KVM_FEATURE:
+ return 0;
default:
return -ENXIO;
}
@@ -836,9 +838,18 @@ static int kvm_loongarch_cpucfg_get_attr(struct kvm_vcpu *vcpu,
uint64_t val;
uint64_t __user *uaddr = (uint64_t __user *)attr->addr;
- ret = _kvm_get_cpucfg_mask(attr->attr, &val);
- if (ret)
- return ret;
+ switch (attr->attr) {
+ case 0 ... (KVM_MAX_CPUCFG_REGS - 1):
+ ret = _kvm_get_cpucfg_mask(attr->attr, &val);
+ if (ret)
+ return ret;
+ break;
+ case CPUCFG_KVM_FEATURE:
+ val = vcpu->kvm->arch.pv_features & LOONGARCH_PV_FEAT_MASK;
+ break;
+ default:
+ return -ENXIO;
+ }
put_user(val, uaddr);
@@ -884,7 +895,29 @@ static int kvm_loongarch_vcpu_get_attr(struct kvm_vcpu *vcpu,
static int kvm_loongarch_cpucfg_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
- return -ENXIO;
+ u64 __user *user = (u64 __user *)attr->addr;
+ u64 val, valid;
+ struct kvm *kvm = vcpu->kvm;
+
+ switch (attr->attr) {
+ case CPUCFG_KVM_FEATURE:
+ if (get_user(val, user))
+ return -EFAULT;
+
+ valid = LOONGARCH_PV_FEAT_MASK;
+ if (val & ~valid)
+ return -EINVAL;
+
+ /* All vCPUs need set the same pv features */
+ if ((kvm->arch.pv_features & LOONGARCH_PV_FEAT_UPDATED) &&
+ ((kvm->arch.pv_features & valid) != val))
+ return -EINVAL;
+ kvm->arch.pv_features = val | LOONGARCH_PV_FEAT_UPDATED;
+ return 0;
+
+ default:
+ return -ENXIO;
+ }
}
static int kvm_loongarch_pvtime_set_attr(struct kvm_vcpu *vcpu,
diff --git a/arch/loongarch/kvm/vm.c b/arch/loongarch/kvm/vm.c
index f9604bc2b3ea..855f125a5aaa 100644
--- a/arch/loongarch/kvm/vm.c
+++ b/arch/loongarch/kvm/vm.c
@@ -5,6 +5,7 @@
#include <linux/kvm_host.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm_vcpu.h>
const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
KVM_GENERIC_VM_STATS(),
@@ -39,6 +40,11 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
spin_lock_init(&kvm->arch.phyid_map_lock);
kvm_init_vmcs(kvm);
+ kvm->arch.pv_capability = KVM_FEATURE_IPI;
+ if (kvm_pvtime_supported())
+ kvm->arch.pv_capability |= KVM_FEATURE_STEAL_TIME;
+ /* Enable all pv features by default */
+ kvm->arch.pv_features = kvm->arch.pv_capability;
kvm->arch.gpa_size = BIT(cpu_vabits - 1);
kvm->arch.root_level = CONFIG_PGTABLE_LEVELS - 1;
kvm->arch.invalid_ptes[0] = 0;
@@ -122,6 +128,12 @@ static int kvm_vm_feature_has_attr(struct kvm *kvm, struct kvm_device_attr *attr
if (cpu_has_lbt_mips)
return 0;
return -ENXIO;
+ case KVM_LOONGARCH_VM_FEAT_PV_IPI:
+ return 0;
+ case KVM_LOONGARCH_VM_FEAT_PV_STEALTIME:
+ if (kvm_pvtime_supported())
+ return 0;
+ return -ENXIO;
default:
return -ENXIO;
}
--
2.39.3
