[PULL 31/65] target/riscv: Create an KVM AIA irqchip

Alistair Francis posted 65 patches 1 year, 2 months ago
Maintainers: "Daniel P. Berrangé" <berrange@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Weiwei Li <liweiwei@iscas.ac.cn>, Daniel Henrique Barboza <dbarboza@ventanamicro.com>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>, Laurent Vivier <laurent@vivier.eu>, Peter Maydell <peter.maydell@linaro.org>, "Alex Bennée" <alex.bennee@linaro.org>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Thomas Huth <thuth@redhat.com>, Wainer dos Santos Moschetta <wainersm@redhat.com>, Beraldo Leal <bleal@redhat.com>, Cleber Rosa <crosa@redhat.com>
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[PULL 31/65] target/riscv: Create an KVM AIA irqchip
Posted by Alistair Francis 1 year, 2 months ago
From: Yong-Xuan Wang <yongxuan.wang@sifive.com>

We create a vAIA chip by using the KVM_DEV_TYPE_RISCV_AIA and then set up
the chip with the KVM_DEV_RISCV_AIA_GRP_* APIs.
We also extend KVM accelerator to specify the KVM AIA mode. The "riscv-aia"
parameter is passed along with --accel in QEMU command-line.
1) "riscv-aia=emul": IMSIC is emulated by hypervisor
2) "riscv-aia=hwaccel": use hardware guest IMSIC
3) "riscv-aia=auto": use the hardware guest IMSICs whenever available
                     otherwise we fallback to software emulation.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20230727102439.22554-4-yongxuan.wang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/kvm_riscv.h |   4 +
 target/riscv/kvm.c       | 186 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 190 insertions(+)

diff --git a/target/riscv/kvm_riscv.h b/target/riscv/kvm_riscv.h
index e3ba935808..7d4b7c60e2 100644
--- a/target/riscv/kvm_riscv.h
+++ b/target/riscv/kvm_riscv.h
@@ -22,5 +22,9 @@
 void kvm_riscv_init_user_properties(Object *cpu_obj);
 void kvm_riscv_reset_vcpu(RISCVCPU *cpu);
 void kvm_riscv_set_irq(RISCVCPU *cpu, int irq, int level);
+void kvm_riscv_aia_create(MachineState *machine, uint64_t group_shift,
+                          uint64_t aia_irq_num, uint64_t aia_msi_num,
+                          uint64_t aplic_base, uint64_t imsic_base,
+                          uint64_t guest_num);
 
 #endif
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 2953547cb6..6e909d0fdd 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -36,6 +36,7 @@
 #include "exec/address-spaces.h"
 #include "hw/boards.h"
 #include "hw/irq.h"
+#include "hw/intc/riscv_imsic.h"
 #include "qemu/log.h"
 #include "hw/loader.h"
 #include "kvm_riscv.h"
@@ -43,6 +44,7 @@
 #include "chardev/char-fe.h"
 #include "migration/migration.h"
 #include "sysemu/runstate.h"
+#include "hw/riscv/numa.h"
 
 static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
                                  uint64_t idx)
@@ -1035,6 +1037,190 @@ bool kvm_arch_cpu_check_are_resettable(void)
     return true;
 }
 
+static int aia_mode;
+
+static const char *kvm_aia_mode_str(uint64_t mode)
+{
+    switch (mode) {
+    case KVM_DEV_RISCV_AIA_MODE_EMUL:
+        return "emul";
+    case KVM_DEV_RISCV_AIA_MODE_HWACCEL:
+        return "hwaccel";
+    case KVM_DEV_RISCV_AIA_MODE_AUTO:
+    default:
+        return "auto";
+    };
+}
+
+static char *riscv_get_kvm_aia(Object *obj, Error **errp)
+{
+    return g_strdup(kvm_aia_mode_str(aia_mode));
+}
+
+static void riscv_set_kvm_aia(Object *obj, const char *val, Error **errp)
+{
+    if (!strcmp(val, "emul")) {
+        aia_mode = KVM_DEV_RISCV_AIA_MODE_EMUL;
+    } else if (!strcmp(val, "hwaccel")) {
+        aia_mode = KVM_DEV_RISCV_AIA_MODE_HWACCEL;
+    } else if (!strcmp(val, "auto")) {
+        aia_mode = KVM_DEV_RISCV_AIA_MODE_AUTO;
+    } else {
+        error_setg(errp, "Invalid KVM AIA mode");
+        error_append_hint(errp, "Valid values are emul, hwaccel, and auto.\n");
+    }
+}
+
 void kvm_arch_accel_class_init(ObjectClass *oc)
 {
+    object_class_property_add_str(oc, "riscv-aia", riscv_get_kvm_aia,
+                                  riscv_set_kvm_aia);
+    object_class_property_set_description(oc, "riscv-aia",
+                                          "Set KVM AIA mode. Valid values are "
+                                          "emul, hwaccel, and auto. Default "
+                                          "is auto.");
+    object_property_set_default_str(object_class_property_find(oc, "riscv-aia"),
+                                    "auto");
+}
+
+void kvm_riscv_aia_create(MachineState *machine, uint64_t group_shift,
+                          uint64_t aia_irq_num, uint64_t aia_msi_num,
+                          uint64_t aplic_base, uint64_t imsic_base,
+                          uint64_t guest_num)
+{
+    int ret, i;
+    int aia_fd = -1;
+    uint64_t default_aia_mode;
+    uint64_t socket_count = riscv_socket_count(machine);
+    uint64_t max_hart_per_socket = 0;
+    uint64_t socket, base_hart, hart_count, socket_imsic_base, imsic_addr;
+    uint64_t socket_bits, hart_bits, guest_bits;
+
+    aia_fd = kvm_create_device(kvm_state, KVM_DEV_TYPE_RISCV_AIA, false);
+
+    if (aia_fd < 0) {
+        error_report("Unable to create in-kernel irqchip");
+        exit(1);
+    }
+
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                            KVM_DEV_RISCV_AIA_CONFIG_MODE,
+                            &default_aia_mode, false, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to get current KVM AIA mode");
+        exit(1);
+    }
+    qemu_log("KVM AIA: default mode is %s\n",
+             kvm_aia_mode_str(default_aia_mode));
+
+    if (default_aia_mode != aia_mode) {
+        ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                                KVM_DEV_RISCV_AIA_CONFIG_MODE,
+                                &aia_mode, true, NULL);
+        if (ret < 0)
+            warn_report("KVM AIA: failed to set KVM AIA mode");
+        else
+            qemu_log("KVM AIA: set current mode to %s\n",
+                     kvm_aia_mode_str(aia_mode));
+    }
+
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                            KVM_DEV_RISCV_AIA_CONFIG_SRCS,
+                            &aia_irq_num, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to set number of input irq lines");
+        exit(1);
+    }
+
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                            KVM_DEV_RISCV_AIA_CONFIG_IDS,
+                            &aia_msi_num, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to set number of msi");
+        exit(1);
+    }
+
+    socket_bits = find_last_bit(&socket_count, BITS_PER_LONG) + 1;
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                            KVM_DEV_RISCV_AIA_CONFIG_GROUP_BITS,
+                            &socket_bits, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to set group_bits");
+        exit(1);
+    }
+
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                            KVM_DEV_RISCV_AIA_CONFIG_GROUP_SHIFT,
+                            &group_shift, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to set group_shift");
+        exit(1);
+    }
+
+    guest_bits = guest_num == 0 ? 0 :
+                 find_last_bit(&guest_num, BITS_PER_LONG) + 1;
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                            KVM_DEV_RISCV_AIA_CONFIG_GUEST_BITS,
+                            &guest_bits, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to set guest_bits");
+        exit(1);
+    }
+
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_ADDR,
+                            KVM_DEV_RISCV_AIA_ADDR_APLIC,
+                            &aplic_base, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to set the base address of APLIC");
+        exit(1);
+    }
+
+    for (socket = 0; socket < socket_count; socket++) {
+        socket_imsic_base = imsic_base + socket * (1U << group_shift);
+        hart_count = riscv_socket_hart_count(machine, socket);
+        base_hart = riscv_socket_first_hartid(machine, socket);
+
+        if (max_hart_per_socket < hart_count) {
+            max_hart_per_socket = hart_count;
+        }
+
+        for (i = 0; i < hart_count; i++) {
+            imsic_addr = socket_imsic_base + i * IMSIC_HART_SIZE(guest_bits);
+            ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_ADDR,
+                                    KVM_DEV_RISCV_AIA_ADDR_IMSIC(i + base_hart),
+                                    &imsic_addr, true, NULL);
+            if (ret < 0) {
+                error_report("KVM AIA: failed to set the IMSIC address for hart %d", i);
+                exit(1);
+            }
+        }
+    }
+
+    hart_bits = find_last_bit(&max_hart_per_socket, BITS_PER_LONG) + 1;
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
+                            KVM_DEV_RISCV_AIA_CONFIG_HART_BITS,
+                            &hart_bits, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: failed to set hart_bits");
+        exit(1);
+    }
+
+    if (kvm_has_gsi_routing()) {
+        for (uint64_t idx = 0; idx < aia_irq_num + 1; ++idx) {
+            /* KVM AIA only has one APLIC instance */
+            kvm_irqchip_add_irq_route(kvm_state, idx, 0, idx);
+        }
+        kvm_gsi_routing_allowed = true;
+        kvm_irqchip_commit_routes(kvm_state);
+    }
+
+    ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CTRL,
+                            KVM_DEV_RISCV_AIA_CTRL_INIT,
+                            NULL, true, NULL);
+    if (ret < 0) {
+        error_report("KVM AIA: initialized fail");
+        exit(1);
+    }
+
+    kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
 }
-- 
2.41.0