[PATCH v7 00/20] target/riscv, KVM: fixes and enhancements

[PATCH v7 00/20] target/riscv, KVM: fixes and enhancements

[Daniel Henrique Barboza]

Hi,

This version includes most of the fixes and changes suggested in the v6
review [1].

Unfortunately we weren't able to proceed with Drew's suggestion to avoid
assigning 'name' and 'description' during runtime in patch 11 because
some Gitlab runners (clang-user and tsan-build) complained about
misa_ext_info_arr[] not being a compiler-time constant. I documented
this 'clang' situation in patch 11 commit msg.

The change to use __builtin_ctz() instead of ctz32() was kept because
it's clearer to use the MISA bits (RVA, RVC ...) as input for
MISA_EXT_INFO() than doing a calculation with (letter - 'A').

All other suggestions from both Drew and Phil were implemented. 'sudo'
references from commit msgs were removed from patches 1 and 2 as
suggested by Michael (R-bs were kept).

Series based on top of Alistair's riscv-to-apply.next.

Patches missing review: 11, 12

Changes from v6:
- patches 1 and 2: removed 'sudo' references from commit msgs
- patch 11:
  - use __builtin_ctz() instead of ctz32() in MISA_EXT_INFO
  - renamed getter to riscv_get_misa_ext_description()
  - do input/output validation in both getters
- patch 12:
  - use object_property_find() to skip the property if it already exists
- v6 link: https://lists.gnu.org/archive/html/qemu-devel/2023-06/msg06353.html

[1] https://lists.gnu.org/archive/html/qemu-devel/2023-06/msg06353.html

Daniel Henrique Barboza (20):
  target/riscv: skip features setup for KVM CPUs
  hw/riscv/virt.c: skip 'mmu-type' FDT if satp mode not set
  target/riscv/cpu.c: restrict 'mvendorid' value
  target/riscv/cpu.c: restrict 'mimpid' value
  target/riscv/cpu.c: restrict 'marchid' value
  target/riscv: use KVM scratch CPUs to init KVM properties
  target/riscv: read marchid/mimpid in kvm_riscv_init_machine_ids()
  target/riscv: handle mvendorid/marchid/mimpid for KVM CPUs
  linux-headers: Update to v6.4-rc1
  target/riscv/kvm.c: init 'misa_ext_mask' with scratch CPU
  target/riscv/cpu: add misa_ext_info_arr[]
  target/riscv: add KVM specific MISA properties
  target/riscv/kvm.c: update KVM MISA bits
  target/riscv/kvm.c: add multi-letter extension KVM properties
  target/riscv/cpu.c: add satp_mode properties earlier
  target/riscv/cpu.c: remove priv_ver check from riscv_isa_string_ext()
  target/riscv/cpu.c: create KVM mock properties
  target/riscv: update multi-letter extension KVM properties
  target/riscv/kvm.c: add kvmconfig_get_cfg_addr() helper
  target/riscv/kvm.c: read/write (cbom|cboz)_blocksize in KVM

 hw/riscv/virt.c                               |  14 +-
 include/standard-headers/linux/const.h        |   2 +-
 include/standard-headers/linux/virtio_blk.h   |  18 +-
 .../standard-headers/linux/virtio_config.h    |   6 +
 include/standard-headers/linux/virtio_net.h   |   1 +
 linux-headers/asm-arm64/kvm.h                 |  33 ++
 linux-headers/asm-riscv/kvm.h                 |  53 +-
 linux-headers/asm-riscv/unistd.h              |   9 +
 linux-headers/asm-s390/unistd_32.h            |   1 +
 linux-headers/asm-s390/unistd_64.h            |   1 +
 linux-headers/asm-x86/kvm.h                   |   3 +
 linux-headers/linux/const.h                   |   2 +-
 linux-headers/linux/kvm.h                     |  12 +-
 linux-headers/linux/psp-sev.h                 |   7 +
 linux-headers/linux/userfaultfd.h             |  17 +-
 target/riscv/cpu.c                            | 341 ++++++++++--
 target/riscv/cpu.h                            |   7 +-
 target/riscv/kvm.c                            | 499 +++++++++++++++++-
 target/riscv/kvm_riscv.h                      |   1 +
 19 files changed, 940 insertions(+), 87 deletions(-)

-- 
2.41.0

[PATCH v7 01/20] target/riscv: skip features setup for KVM CPUs

[Daniel Henrique Barboza]

As it is today it's not possible to use '-cpu host' if the RISC-V host
has RVH enabled. This is the resulting error:

$ ./qemu/build/qemu-system-riscv64 \
    -machine virt,accel=kvm -m 2G -smp 1 \
    -nographic -snapshot -kernel ./guest_imgs/Image  \
    -initrd ./guest_imgs/rootfs_kvm_riscv64.img \
    -append "earlycon=sbi root=/dev/ram rw" \
    -cpu host
qemu-system-riscv64: H extension requires priv spec 1.12.0

This happens because we're checking for priv spec for all CPUs, and
since we're not setting  env->priv_ver for the 'host' CPU, it's being
default to zero (i.e. PRIV_SPEC_1_10_0).

In reality env->priv_ver does not make sense when running with the KVM
'host' CPU. It's used to gate certain CSRs/extensions during translation
to make them unavailable if the hart declares an older spec version. It
doesn't have any other use. E.g. OpenSBI version 1.2 retrieves the spec
checking if the CSR_MCOUNTEREN, CSR_MCOUNTINHIBIT and CSR_MENVCFG CSRs
are available [1].

'priv_ver' is just one example. We're doing a lot of feature validation
and setup during riscv_cpu_realize() that it doesn't apply to KVM CPUs.
Validating the feature set for those CPUs is a KVM problem that should
be handled in KVM specific code.

The new riscv_cpu_realize_tcg() helper contains all validation logic that
are applicable to TCG CPUs only. riscv_cpu_realize() verifies if we're
running TCG and, if it's the case, proceed with the usual TCG realize()
logic.

[1] lib/sbi/sbi_hart.c, hart_detect_features()

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/cpu.c | 35 +++++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index fb8458bf74..bbb201a2b3 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -34,6 +34,7 @@
 #include "migration/vmstate.h"
 #include "fpu/softfloat-helpers.h"
 #include "sysemu/kvm.h"
+#include "sysemu/tcg.h"
 #include "kvm_riscv.h"
 #include "tcg/tcg.h"
 
@@ -1308,20 +1309,12 @@ static void riscv_cpu_validate_misa_priv(CPURISCVState *env, Error **errp)
     }
 }
 
-static void riscv_cpu_realize(DeviceState *dev, Error **errp)
+static void riscv_cpu_realize_tcg(DeviceState *dev, Error **errp)
 {
-    CPUState *cs = CPU(dev);
     RISCVCPU *cpu = RISCV_CPU(dev);
     CPURISCVState *env = &cpu->env;
-    RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
     Error *local_err = NULL;
 
-    cpu_exec_realizefn(cs, &local_err);
-    if (local_err != NULL) {
-        error_propagate(errp, local_err);
-        return;
-    }
-
     riscv_cpu_validate_misa_mxl(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
@@ -1356,7 +1349,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     }
 
 #ifndef CONFIG_USER_ONLY
-    cs->tcg_cflags |= CF_PCREL;
+    CPU(dev)->tcg_cflags |= CF_PCREL;
 
     if (cpu->cfg.ext_sstc) {
         riscv_timer_init(cpu);
@@ -1369,6 +1362,28 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         }
      }
 #endif
+}
+
+static void riscv_cpu_realize(DeviceState *dev, Error **errp)
+{
+    CPUState *cs = CPU(dev);
+    RISCVCPU *cpu = RISCV_CPU(dev);
+    RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
+    Error *local_err = NULL;
+
+    cpu_exec_realizefn(cs, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    if (tcg_enabled()) {
+        riscv_cpu_realize_tcg(dev, &local_err);
+        if (local_err != NULL) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
 
     riscv_cpu_finalize_features(cpu, &local_err);
     if (local_err != NULL) {
-- 
2.41.0

[PATCH v7 02/20] hw/riscv/virt.c: skip 'mmu-type' FDT if satp mode not set

[Daniel Henrique Barboza]

The absence of a satp mode in riscv_host_cpu_init() is causing the
following error:

$ ./qemu/build/qemu-system-riscv64  -machine virt,accel=kvm \
    -m 2G -smp 1  -nographic -snapshot \
    -kernel ./guest_imgs/Image \
    -initrd ./guest_imgs/rootfs_kvm_riscv64.img \
    -append "earlycon=sbi root=/dev/ram rw" \
    -cpu host
**
ERROR:../target/riscv/cpu.c:320:satp_mode_str: code should not be
reached
Bail out! ERROR:../target/riscv/cpu.c:320:satp_mode_str: code should
not be reached
Aborted

The error is triggered from create_fdt_socket_cpus() in hw/riscv/virt.c.
It's trying to get satp_mode_str for a NULL cpu->cfg.satp_mode.map.

For this KVM cpu we would need to inherit the satp supported modes
from the RISC-V host. At this moment this is not possible because the
KVM driver does not support it. And even when it does we can't just let
this broken for every other older kernel.

Since mmu-type is not a required node, according to [1], skip the
'mmu-type' FDT node if there's no satp_mode set. We'll revisit this
logic when we can get satp information from KVM.

[1] https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/cpu.yaml

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/riscv/virt.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index 95708d890e..f025a0fcaf 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -243,13 +243,13 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int socket,
             s->soc[socket].hartid_base + cpu);
         qemu_fdt_add_subnode(ms->fdt, cpu_name);
 
-        satp_mode_max = satp_mode_max_from_map(
-            s->soc[socket].harts[cpu].cfg.satp_mode.map);
-        sv_name = g_strdup_printf("riscv,%s",
-                                  satp_mode_str(satp_mode_max, is_32_bit));
-        qemu_fdt_setprop_string(ms->fdt, cpu_name, "mmu-type", sv_name);
-        g_free(sv_name);
-
+        if (cpu_ptr->cfg.satp_mode.supported != 0) {
+            satp_mode_max = satp_mode_max_from_map(cpu_ptr->cfg.satp_mode.map);
+            sv_name = g_strdup_printf("riscv,%s",
+                                      satp_mode_str(satp_mode_max, is_32_bit));
+            qemu_fdt_setprop_string(ms->fdt, cpu_name, "mmu-type", sv_name);
+            g_free(sv_name);
+        }
 
         name = riscv_isa_string(cpu_ptr);
         qemu_fdt_setprop_string(ms->fdt, cpu_name, "riscv,isa", name);
-- 
2.41.0

[PATCH v7 03/20] target/riscv/cpu.c: restrict 'mvendorid' value

[Daniel Henrique Barboza]

We're going to change the handling of mvendorid/marchid/mimpid by the
KVM driver. Since these are always present in all CPUs let's put the
same validation for everyone.

It doesn't make sense to allow 'mvendorid' to be different than it
is already set in named (vendor) CPUs. Generic (dynamic) CPUs can have
any 'mvendorid' they want.

Change 'mvendorid' to be a class property created via
'object_class_property_add', instead of using the DEFINE_PROP_UINT32()
macro. This allow us to define a custom setter for it that will verify,
for named CPUs, if mvendorid is different than it is already set by the
CPU. This is the error thrown for the 'veyron-v1' CPU if 'mvendorid' is
set to an invalid value:

$ qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mvendorid=2
qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mvendorid=2:
    Unable to change veyron-v1-riscv-cpu mvendorid (0x61f)

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.c | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index bbb201a2b3..652988db25 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1730,7 +1730,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
 static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
 
-    DEFINE_PROP_UINT32("mvendorid", RISCVCPU, cfg.mvendorid, 0),
     DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
     DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
 
@@ -1817,6 +1816,40 @@ static const struct TCGCPUOps riscv_tcg_ops = {
 #endif /* !CONFIG_USER_ONLY */
 };
 
+static bool riscv_cpu_is_dynamic(Object *cpu_obj)
+{
+    return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
+}
+
+static void cpu_set_mvendorid(Object *obj, Visitor *v, const char *name,
+                              void *opaque, Error **errp)
+{
+    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    uint32_t prev_val = cpu->cfg.mvendorid;
+    uint32_t value;
+
+    if (!visit_type_uint32(v, name, &value, errp)) {
+        return;
+    }
+
+    if (!dynamic_cpu && prev_val != value) {
+        error_setg(errp, "Unable to change %s mvendorid (0x%x)",
+                   object_get_typename(obj), prev_val);
+        return;
+    }
+
+    cpu->cfg.mvendorid = value;
+}
+
+static void cpu_get_mvendorid(Object *obj, Visitor *v, const char *name,
+                              void *opaque, Error **errp)
+{
+    bool value = RISCV_CPU(obj)->cfg.mvendorid;
+
+    visit_type_bool(v, name, &value, errp);
+}
+
 static void riscv_cpu_class_init(ObjectClass *c, void *data)
 {
     RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
@@ -1848,6 +1881,9 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
     cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml;
     cc->tcg_ops = &riscv_tcg_ops;
 
+    object_class_property_add(c, "mvendorid", "uint32", cpu_get_mvendorid,
+                              cpu_set_mvendorid, NULL, NULL);
+
     device_class_set_props(dc, riscv_cpu_properties);
 }
 
-- 
2.41.0

[PATCH v7 04/20] target/riscv/cpu.c: restrict 'mimpid' value

[Daniel Henrique Barboza]

Following the same logic used with 'mvendorid' let's also restrict
'mimpid' for named CPUs. Generic CPUs keep setting the value freely.

Note that we're getting rid of the default RISCV_CPU_MARCHID value. The
reason is that this is not a good default since it's dynamic, changing
with with every QEMU version, regardless of whether the actual
implementation of the CPU changed from one QEMU version to the other.
Named CPU should set it to a meaningful value instead and generic CPUs
can set whatever they want.

This is the error thrown for an invalid 'mimpid' value for the veyron-v1
CPU:

$ ./qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mimpid=2
qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mimpid=2:
    Unable to change veyron-v1-riscv-cpu mimpid (0x111)

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 652988db25..a0ac1ba2ac 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -43,7 +43,6 @@
 #define RISCV_CPU_MARCHID   ((QEMU_VERSION_MAJOR << 16) | \
                              (QEMU_VERSION_MINOR << 8)  | \
                              (QEMU_VERSION_MICRO))
-#define RISCV_CPU_MIMPID    RISCV_CPU_MARCHID
 
 static const char riscv_single_letter_exts[] = "IEMAFDQCPVH";
 
@@ -1731,7 +1730,6 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
 
     DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
-    DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
 
 #ifndef CONFIG_USER_ONLY
     DEFINE_PROP_UINT64("resetvec", RISCVCPU, env.resetvec, DEFAULT_RSTVEC),
@@ -1850,6 +1848,35 @@ static void cpu_get_mvendorid(Object *obj, Visitor *v, const char *name,
     visit_type_bool(v, name, &value, errp);
 }
 
+static void cpu_set_mimpid(Object *obj, Visitor *v, const char *name,
+                           void *opaque, Error **errp)
+{
+    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    uint64_t prev_val = cpu->cfg.mimpid;
+    uint64_t value;
+
+    if (!visit_type_uint64(v, name, &value, errp)) {
+        return;
+    }
+
+    if (!dynamic_cpu && prev_val != value) {
+        error_setg(errp, "Unable to change %s mimpid (0x%" PRIu64 ")",
+                   object_get_typename(obj), prev_val);
+        return;
+    }
+
+    cpu->cfg.mimpid = value;
+}
+
+static void cpu_get_mimpid(Object *obj, Visitor *v, const char *name,
+                           void *opaque, Error **errp)
+{
+    bool value = RISCV_CPU(obj)->cfg.mimpid;
+
+    visit_type_bool(v, name, &value, errp);
+}
+
 static void riscv_cpu_class_init(ObjectClass *c, void *data)
 {
     RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
@@ -1884,6 +1911,9 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
     object_class_property_add(c, "mvendorid", "uint32", cpu_get_mvendorid,
                               cpu_set_mvendorid, NULL, NULL);
 
+    object_class_property_add(c, "mimpid", "uint64", cpu_get_mimpid,
+                              cpu_set_mimpid, NULL, NULL);
+
     device_class_set_props(dc, riscv_cpu_properties);
 }
 
-- 
2.41.0

[PATCH v7 05/20] target/riscv/cpu.c: restrict 'marchid' value

[Daniel Henrique Barboza]

'marchid' shouldn't be set to a different value as previously set for
named CPUs.

For all other CPUs it shouldn't be freely set either - the spec requires
that 'marchid' can't have the MSB (most significant bit) set and every
other bit set to zero, i.e. 0x80000000 is an invalid 'marchid' value for
32 bit CPUs.

As with 'mimpid', setting a default value based on the current QEMU
version is not a good idea because it implies that the CPU
implementation changes from one QEMU version to the other. Named CPUs
should set 'marchid' to a meaningful value instead, and generic CPUs can
set to any valid value.

For the 'veyron-v1' CPU this is the error thrown if 'marchid' is set to
a different val:

$ ./build/qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,marchid=0x80000000
qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.marchid=0x80000000:
    Unable to change veyron-v1-riscv-cpu marchid (0x8000000000010000)

And, for generics CPUs, this is the error when trying to set to an
invalid val:

$ ./build/qemu-system-riscv64 -M virt -nographic -cpu rv64,marchid=0x8000000000000000
qemu-system-riscv64: can't apply global rv64-riscv-cpu.marchid=0x8000000000000000:
    Unable to set marchid with MSB (64) bit set and the remaining bits zero

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.c | 60 ++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 53 insertions(+), 7 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index a0ac1ba2ac..a05b76238b 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -39,11 +39,6 @@
 #include "tcg/tcg.h"
 
 /* RISC-V CPU definitions */
-
-#define RISCV_CPU_MARCHID   ((QEMU_VERSION_MAJOR << 16) | \
-                             (QEMU_VERSION_MINOR << 8)  | \
-                             (QEMU_VERSION_MICRO))
-
 static const char riscv_single_letter_exts[] = "IEMAFDQCPVH";
 
 struct isa_ext_data {
@@ -1729,8 +1724,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
 static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
 
-    DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
-
 #ifndef CONFIG_USER_ONLY
     DEFINE_PROP_UINT64("resetvec", RISCVCPU, env.resetvec, DEFAULT_RSTVEC),
 #endif
@@ -1877,6 +1870,56 @@ static void cpu_get_mimpid(Object *obj, Visitor *v, const char *name,
     visit_type_bool(v, name, &value, errp);
 }
 
+static void cpu_set_marchid(Object *obj, Visitor *v, const char *name,
+                            void *opaque, Error **errp)
+{
+    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    uint64_t prev_val = cpu->cfg.marchid;
+    uint64_t value, invalid_val;
+    uint32_t mxlen = 0;
+
+    if (!visit_type_uint64(v, name, &value, errp)) {
+        return;
+    }
+
+    if (!dynamic_cpu && prev_val != value) {
+        error_setg(errp, "Unable to change %s marchid (0x%" PRIu64 ")",
+                   object_get_typename(obj), prev_val);
+        return;
+    }
+
+    switch (riscv_cpu_mxl(&cpu->env)) {
+    case MXL_RV32:
+        mxlen = 32;
+        break;
+    case MXL_RV64:
+    case MXL_RV128:
+        mxlen = 64;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    invalid_val = 1LL << (mxlen - 1);
+
+    if (value == invalid_val) {
+        error_setg(errp, "Unable to set marchid with MSB (%u) bit set "
+                         "and the remaining bits zero", mxlen);
+        return;
+    }
+
+    cpu->cfg.marchid = value;
+}
+
+static void cpu_get_marchid(Object *obj, Visitor *v, const char *name,
+                           void *opaque, Error **errp)
+{
+    bool value = RISCV_CPU(obj)->cfg.marchid;
+
+    visit_type_bool(v, name, &value, errp);
+}
+
 static void riscv_cpu_class_init(ObjectClass *c, void *data)
 {
     RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
@@ -1914,6 +1957,9 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
     object_class_property_add(c, "mimpid", "uint64", cpu_get_mimpid,
                               cpu_set_mimpid, NULL, NULL);
 
+    object_class_property_add(c, "marchid", "uint64", cpu_get_marchid,
+                              cpu_set_marchid, NULL, NULL);
+
     device_class_set_props(dc, riscv_cpu_properties);
 }
 
-- 
2.41.0

[PATCH v7 06/20] target/riscv: use KVM scratch CPUs to init KVM properties

[Daniel Henrique Barboza]

Certain validations, such as the validations done for the machine IDs
(mvendorid/marchid/mimpid), are done before starting the CPU.
Non-dynamic (named) CPUs tries to match user input with a preset
default. As it is today we can't prefetch a KVM default for these cases
because we're only able to read/write KVM regs after the vcpu is
spinning.

Our target/arm friends use a concept called "scratch CPU", which
consists of creating a vcpu for doing queries and validations and so on,
which is discarded shortly after use [1]. This is a suitable solution
for what we need so let's implement it in target/riscv as well.

kvm_riscv_init_machine_ids() will be used to do any pre-launch setup for
KVM CPUs, via riscv_cpu_add_user_properties(). The function will create
a KVM scratch CPU, fetch KVM regs that work as default values for user
properties, and then discard the scratch CPU afterwards.

We're starting by initializing 'mvendorid'. This concept will be used to
init other KVM specific properties in the next patches as well.

[1] target/arm/kvm.c, kvm_arm_create_scratch_host_vcpu()

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.c       |  6 +++
 target/riscv/kvm.c       | 85 ++++++++++++++++++++++++++++++++++++++++
 target/riscv/kvm_riscv.h |  1 +
 3 files changed, 92 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index a05b76238b..58439a05d1 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1710,6 +1710,12 @@ static void riscv_cpu_add_user_properties(Object *obj)
     Property *prop;
     DeviceState *dev = DEVICE(obj);
 
+#ifndef CONFIG_USER_ONLY
+    if (kvm_enabled()) {
+        kvm_riscv_init_user_properties(obj);
+    }
+#endif
+
     riscv_cpu_add_misa_properties(obj);
 
     for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 0f932a5b96..37f0f70794 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -309,6 +309,91 @@ static void kvm_riscv_put_regs_timer(CPUState *cs)
     env->kvm_timer_dirty = false;
 }
 
+typedef struct KVMScratchCPU {
+    int kvmfd;
+    int vmfd;
+    int cpufd;
+} KVMScratchCPU;
+
+/*
+ * Heavily inspired by kvm_arm_create_scratch_host_vcpu()
+ * from target/arm/kvm.c.
+ */
+static bool kvm_riscv_create_scratch_vcpu(KVMScratchCPU *scratch)
+{
+    int kvmfd = -1, vmfd = -1, cpufd = -1;
+
+    kvmfd = qemu_open_old("/dev/kvm", O_RDWR);
+    if (kvmfd < 0) {
+        goto err;
+    }
+    do {
+        vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
+    } while (vmfd == -1 && errno == EINTR);
+    if (vmfd < 0) {
+        goto err;
+    }
+    cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
+    if (cpufd < 0) {
+        goto err;
+    }
+
+    scratch->kvmfd =  kvmfd;
+    scratch->vmfd = vmfd;
+    scratch->cpufd = cpufd;
+
+    return true;
+
+ err:
+    if (cpufd >= 0) {
+        close(cpufd);
+    }
+    if (vmfd >= 0) {
+        close(vmfd);
+    }
+    if (kvmfd >= 0) {
+        close(kvmfd);
+    }
+
+    return false;
+}
+
+static void kvm_riscv_destroy_scratch_vcpu(KVMScratchCPU *scratch)
+{
+    close(scratch->cpufd);
+    close(scratch->vmfd);
+    close(scratch->kvmfd);
+}
+
+static void kvm_riscv_init_machine_ids(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
+{
+    CPURISCVState *env = &cpu->env;
+    struct kvm_one_reg reg;
+    int ret;
+
+    reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                              KVM_REG_RISCV_CONFIG_REG(mvendorid));
+    reg.addr = (uint64_t)&cpu->cfg.mvendorid;
+    ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
+    if (ret != 0) {
+        error_report("Unable to retrieve mvendorid from host, error %d", ret);
+    }
+}
+
+void kvm_riscv_init_user_properties(Object *cpu_obj)
+{
+    RISCVCPU *cpu = RISCV_CPU(cpu_obj);
+    KVMScratchCPU kvmcpu;
+
+    if (!kvm_riscv_create_scratch_vcpu(&kvmcpu)) {
+        return;
+    }
+
+    kvm_riscv_init_machine_ids(cpu, &kvmcpu);
+
+    kvm_riscv_destroy_scratch_vcpu(&kvmcpu);
+}
+
 const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
 };
diff --git a/target/riscv/kvm_riscv.h b/target/riscv/kvm_riscv.h
index ed281bdce0..e3ba935808 100644
--- a/target/riscv/kvm_riscv.h
+++ b/target/riscv/kvm_riscv.h
@@ -19,6 +19,7 @@
 #ifndef QEMU_KVM_RISCV_H
 #define QEMU_KVM_RISCV_H
 
+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);
 
-- 
2.41.0

[PATCH v7 07/20] target/riscv: read marchid/mimpid in kvm_riscv_init_machine_ids()

[Daniel Henrique Barboza]

Allow 'marchid' and 'mimpid' to also be initialized in
kvm_riscv_init_machine_ids().

After this change, the handling of mvendorid/marchid/mimpid for the
'host' CPU type will be equal to what we already have for TCG named
CPUs, i.e. the user is not able to set these values to a different val
than the one that is already preset.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/kvm.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 37f0f70794..cd2974c663 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -378,6 +378,22 @@ static void kvm_riscv_init_machine_ids(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
     if (ret != 0) {
         error_report("Unable to retrieve mvendorid from host, error %d", ret);
     }
+
+    reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                              KVM_REG_RISCV_CONFIG_REG(marchid));
+    reg.addr = (uint64_t)&cpu->cfg.marchid;
+    ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
+    if (ret != 0) {
+        error_report("Unable to retrieve marchid from host, error %d", ret);
+    }
+
+    reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                              KVM_REG_RISCV_CONFIG_REG(mimpid));
+    reg.addr = (uint64_t)&cpu->cfg.mimpid;
+    ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
+    if (ret != 0) {
+        error_report("Unable to retrieve mimpid from host, error %d", ret);
+    }
 }
 
 void kvm_riscv_init_user_properties(Object *cpu_obj)
-- 
2.41.0

[PATCH v7 08/20] target/riscv: handle mvendorid/marchid/mimpid for KVM CPUs

[Daniel Henrique Barboza]

After changing user validation for mvendorid/marchid/mimpid to guarantee
that the value is validated on user input time, coupled with the work in
fetching KVM default values for them by using a scratch CPU, we're
certain that the values in cpu->cfg.(mvendorid|marchid|mimpid) are
already good to be written back to KVM.

There's no need to write the values back for 'host' type CPUs since the
values can't be changed, so let's do that just for generic CPUs.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/kvm.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index cd2974c663..602727cdfd 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -495,6 +495,33 @@ void kvm_arch_init_irq_routing(KVMState *s)
 {
 }
 
+static int kvm_vcpu_set_machine_ids(RISCVCPU *cpu, CPUState *cs)
+{
+    CPURISCVState *env = &cpu->env;
+    uint64_t id;
+    int ret;
+
+    id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                          KVM_REG_RISCV_CONFIG_REG(mvendorid));
+    ret = kvm_set_one_reg(cs, id, &cpu->cfg.mvendorid);
+    if (ret != 0) {
+        return ret;
+    }
+
+    id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                          KVM_REG_RISCV_CONFIG_REG(marchid));
+    ret = kvm_set_one_reg(cs, id, &cpu->cfg.marchid);
+    if (ret != 0) {
+        return ret;
+    }
+
+    id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                          KVM_REG_RISCV_CONFIG_REG(mimpid));
+    ret = kvm_set_one_reg(cs, id, &cpu->cfg.mimpid);
+
+    return ret;
+}
+
 int kvm_arch_init_vcpu(CPUState *cs)
 {
     int ret = 0;
@@ -513,6 +540,10 @@ int kvm_arch_init_vcpu(CPUState *cs)
     }
     env->misa_ext = isa;
 
+    if (!object_dynamic_cast(OBJECT(cpu), TYPE_RISCV_CPU_HOST)) {
+        ret = kvm_vcpu_set_machine_ids(cpu, cs);
+    }
+
     return ret;
 }
 
-- 
2.41.0

[PATCH v7 09/20] linux-headers: Update to v6.4-rc1

[Daniel Henrique Barboza]

Update to commit ac9a78681b92 ("Linux 6.4-rc1").

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/standard-headers/linux/const.h        |  2 +-
 include/standard-headers/linux/virtio_blk.h   | 18 +++----
 .../standard-headers/linux/virtio_config.h    |  6 +++
 include/standard-headers/linux/virtio_net.h   |  1 +
 linux-headers/asm-arm64/kvm.h                 | 33 ++++++++++++
 linux-headers/asm-riscv/kvm.h                 | 53 ++++++++++++++++++-
 linux-headers/asm-riscv/unistd.h              |  9 ++++
 linux-headers/asm-s390/unistd_32.h            |  1 +
 linux-headers/asm-s390/unistd_64.h            |  1 +
 linux-headers/asm-x86/kvm.h                   |  3 ++
 linux-headers/linux/const.h                   |  2 +-
 linux-headers/linux/kvm.h                     | 12 +++--
 linux-headers/linux/psp-sev.h                 |  7 +++
 linux-headers/linux/userfaultfd.h             | 17 +++++-
 14 files changed, 149 insertions(+), 16 deletions(-)

diff --git a/include/standard-headers/linux/const.h b/include/standard-headers/linux/const.h
index 5e48987251..1eb84b5087 100644
--- a/include/standard-headers/linux/const.h
+++ b/include/standard-headers/linux/const.h
@@ -28,7 +28,7 @@
 #define _BITUL(x)	(_UL(1) << (x))
 #define _BITULL(x)	(_ULL(1) << (x))
 
-#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
+#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1)
 #define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
 
 #define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
diff --git a/include/standard-headers/linux/virtio_blk.h b/include/standard-headers/linux/virtio_blk.h
index 7155b1a470..d7be3cf5e4 100644
--- a/include/standard-headers/linux/virtio_blk.h
+++ b/include/standard-headers/linux/virtio_blk.h
@@ -138,11 +138,11 @@ struct virtio_blk_config {
 
 	/* Zoned block device characteristics (if VIRTIO_BLK_F_ZONED) */
 	struct virtio_blk_zoned_characteristics {
-		uint32_t zone_sectors;
-		uint32_t max_open_zones;
-		uint32_t max_active_zones;
-		uint32_t max_append_sectors;
-		uint32_t write_granularity;
+		__virtio32 zone_sectors;
+		__virtio32 max_open_zones;
+		__virtio32 max_active_zones;
+		__virtio32 max_append_sectors;
+		__virtio32 write_granularity;
 		uint8_t model;
 		uint8_t unused2[3];
 	} zoned;
@@ -239,11 +239,11 @@ struct virtio_blk_outhdr {
  */
 struct virtio_blk_zone_descriptor {
 	/* Zone capacity */
-	uint64_t z_cap;
+	__virtio64 z_cap;
 	/* The starting sector of the zone */
-	uint64_t z_start;
+	__virtio64 z_start;
 	/* Zone write pointer position in sectors */
-	uint64_t z_wp;
+	__virtio64 z_wp;
 	/* Zone type */
 	uint8_t z_type;
 	/* Zone state */
@@ -252,7 +252,7 @@ struct virtio_blk_zone_descriptor {
 };
 
 struct virtio_blk_zone_report {
-	uint64_t nr_zones;
+	__virtio64 nr_zones;
 	uint8_t reserved[56];
 	struct virtio_blk_zone_descriptor zones[];
 };
diff --git a/include/standard-headers/linux/virtio_config.h b/include/standard-headers/linux/virtio_config.h
index 965ee6ae23..8a7d0dc8b0 100644
--- a/include/standard-headers/linux/virtio_config.h
+++ b/include/standard-headers/linux/virtio_config.h
@@ -97,6 +97,12 @@
  */
 #define VIRTIO_F_SR_IOV			37
 
+/*
+ * This feature indicates that the driver passes extra data (besides
+ * identifying the virtqueue) in its device notifications.
+ */
+#define VIRTIO_F_NOTIFICATION_DATA	38
+
 /*
  * This feature indicates that the driver can reset a queue individually.
  */
diff --git a/include/standard-headers/linux/virtio_net.h b/include/standard-headers/linux/virtio_net.h
index c0e797067a..2325485f2c 100644
--- a/include/standard-headers/linux/virtio_net.h
+++ b/include/standard-headers/linux/virtio_net.h
@@ -61,6 +61,7 @@
 #define VIRTIO_NET_F_GUEST_USO6	55	/* Guest can handle USOv6 in. */
 #define VIRTIO_NET_F_HOST_USO	56	/* Host can handle USO in. */
 #define VIRTIO_NET_F_HASH_REPORT  57	/* Supports hash report */
+#define VIRTIO_NET_F_GUEST_HDRLEN  59	/* Guest provides the exact hdr_len value. */
 #define VIRTIO_NET_F_RSS	  60	/* Supports RSS RX steering */
 #define VIRTIO_NET_F_RSC_EXT	  61	/* extended coalescing info */
 #define VIRTIO_NET_F_STANDBY	  62	/* Act as standby for another device
diff --git a/linux-headers/asm-arm64/kvm.h b/linux-headers/asm-arm64/kvm.h
index d7e7bb885e..38e5957526 100644
--- a/linux-headers/asm-arm64/kvm.h
+++ b/linux-headers/asm-arm64/kvm.h
@@ -198,6 +198,15 @@ struct kvm_arm_copy_mte_tags {
 	__u64 reserved[2];
 };
 
+/*
+ * Counter/Timer offset structure. Describe the virtual/physical offset.
+ * To be used with KVM_ARM_SET_COUNTER_OFFSET.
+ */
+struct kvm_arm_counter_offset {
+	__u64 counter_offset;
+	__u64 reserved;
+};
+
 #define KVM_ARM_TAGS_TO_GUEST		0
 #define KVM_ARM_TAGS_FROM_GUEST		1
 
@@ -363,6 +372,10 @@ enum {
 	KVM_REG_ARM_VENDOR_HYP_BIT_PTP		= 1,
 };
 
+/* Device Control API on vm fd */
+#define KVM_ARM_VM_SMCCC_CTRL		0
+#define   KVM_ARM_VM_SMCCC_FILTER	0
+
 /* Device Control API: ARM VGIC */
 #define KVM_DEV_ARM_VGIC_GRP_ADDR	0
 #define KVM_DEV_ARM_VGIC_GRP_DIST_REGS	1
@@ -402,6 +415,8 @@ enum {
 #define KVM_ARM_VCPU_TIMER_CTRL		1
 #define   KVM_ARM_VCPU_TIMER_IRQ_VTIMER		0
 #define   KVM_ARM_VCPU_TIMER_IRQ_PTIMER		1
+#define   KVM_ARM_VCPU_TIMER_IRQ_HVTIMER	2
+#define   KVM_ARM_VCPU_TIMER_IRQ_HPTIMER	3
 #define KVM_ARM_VCPU_PVTIME_CTRL	2
 #define   KVM_ARM_VCPU_PVTIME_IPA	0
 
@@ -458,6 +473,24 @@ enum {
 /* run->fail_entry.hardware_entry_failure_reason codes. */
 #define KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED	(1ULL << 0)
 
+enum kvm_smccc_filter_action {
+	KVM_SMCCC_FILTER_HANDLE = 0,
+	KVM_SMCCC_FILTER_DENY,
+	KVM_SMCCC_FILTER_FWD_TO_USER,
+
+};
+
+struct kvm_smccc_filter {
+	__u32 base;
+	__u32 nr_functions;
+	__u8 action;
+	__u8 pad[15];
+};
+
+/* arm64-specific KVM_EXIT_HYPERCALL flags */
+#define KVM_HYPERCALL_EXIT_SMC		(1U << 0)
+#define KVM_HYPERCALL_EXIT_16BIT	(1U << 1)
+
 #endif
 
 #endif /* __ARM_KVM_H__ */
diff --git a/linux-headers/asm-riscv/kvm.h b/linux-headers/asm-riscv/kvm.h
index 92af6f3f05..f92790c948 100644
--- a/linux-headers/asm-riscv/kvm.h
+++ b/linux-headers/asm-riscv/kvm.h
@@ -12,6 +12,7 @@
 #ifndef __ASSEMBLY__
 
 #include <linux/types.h>
+#include <asm/bitsperlong.h>
 #include <asm/ptrace.h>
 
 #define __KVM_HAVE_READONLY_MEM
@@ -52,6 +53,7 @@ struct kvm_riscv_config {
 	unsigned long mvendorid;
 	unsigned long marchid;
 	unsigned long mimpid;
+	unsigned long zicboz_block_size;
 };
 
 /* CORE registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
@@ -64,7 +66,7 @@ struct kvm_riscv_core {
 #define KVM_RISCV_MODE_S	1
 #define KVM_RISCV_MODE_U	0
 
-/* CSR registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
+/* General CSR registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
 struct kvm_riscv_csr {
 	unsigned long sstatus;
 	unsigned long sie;
@@ -78,6 +80,17 @@ struct kvm_riscv_csr {
 	unsigned long scounteren;
 };
 
+/* AIA CSR registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
+struct kvm_riscv_aia_csr {
+	unsigned long siselect;
+	unsigned long iprio1;
+	unsigned long iprio2;
+	unsigned long sieh;
+	unsigned long siph;
+	unsigned long iprio1h;
+	unsigned long iprio2h;
+};
+
 /* TIMER registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
 struct kvm_riscv_timer {
 	__u64 frequency;
@@ -105,9 +118,29 @@ enum KVM_RISCV_ISA_EXT_ID {
 	KVM_RISCV_ISA_EXT_SVINVAL,
 	KVM_RISCV_ISA_EXT_ZIHINTPAUSE,
 	KVM_RISCV_ISA_EXT_ZICBOM,
+	KVM_RISCV_ISA_EXT_ZICBOZ,
+	KVM_RISCV_ISA_EXT_ZBB,
+	KVM_RISCV_ISA_EXT_SSAIA,
 	KVM_RISCV_ISA_EXT_MAX,
 };
 
+/*
+ * SBI extension IDs specific to KVM. This is not the same as the SBI
+ * extension IDs defined by the RISC-V SBI specification.
+ */
+enum KVM_RISCV_SBI_EXT_ID {
+	KVM_RISCV_SBI_EXT_V01 = 0,
+	KVM_RISCV_SBI_EXT_TIME,
+	KVM_RISCV_SBI_EXT_IPI,
+	KVM_RISCV_SBI_EXT_RFENCE,
+	KVM_RISCV_SBI_EXT_SRST,
+	KVM_RISCV_SBI_EXT_HSM,
+	KVM_RISCV_SBI_EXT_PMU,
+	KVM_RISCV_SBI_EXT_EXPERIMENTAL,
+	KVM_RISCV_SBI_EXT_VENDOR,
+	KVM_RISCV_SBI_EXT_MAX,
+};
+
 /* Possible states for kvm_riscv_timer */
 #define KVM_RISCV_TIMER_STATE_OFF	0
 #define KVM_RISCV_TIMER_STATE_ON	1
@@ -118,6 +151,8 @@ enum KVM_RISCV_ISA_EXT_ID {
 /* If you need to interpret the index values, here is the key: */
 #define KVM_REG_RISCV_TYPE_MASK		0x00000000FF000000
 #define KVM_REG_RISCV_TYPE_SHIFT	24
+#define KVM_REG_RISCV_SUBTYPE_MASK	0x0000000000FF0000
+#define KVM_REG_RISCV_SUBTYPE_SHIFT	16
 
 /* Config registers are mapped as type 1 */
 #define KVM_REG_RISCV_CONFIG		(0x01 << KVM_REG_RISCV_TYPE_SHIFT)
@@ -131,8 +166,12 @@ enum KVM_RISCV_ISA_EXT_ID {
 
 /* Control and status registers are mapped as type 3 */
 #define KVM_REG_RISCV_CSR		(0x03 << KVM_REG_RISCV_TYPE_SHIFT)
+#define KVM_REG_RISCV_CSR_GENERAL	(0x0 << KVM_REG_RISCV_SUBTYPE_SHIFT)
+#define KVM_REG_RISCV_CSR_AIA		(0x1 << KVM_REG_RISCV_SUBTYPE_SHIFT)
 #define KVM_REG_RISCV_CSR_REG(name)	\
 		(offsetof(struct kvm_riscv_csr, name) / sizeof(unsigned long))
+#define KVM_REG_RISCV_CSR_AIA_REG(name)	\
+	(offsetof(struct kvm_riscv_aia_csr, name) / sizeof(unsigned long))
 
 /* Timer registers are mapped as type 4 */
 #define KVM_REG_RISCV_TIMER		(0x04 << KVM_REG_RISCV_TYPE_SHIFT)
@@ -152,6 +191,18 @@ enum KVM_RISCV_ISA_EXT_ID {
 /* ISA Extension registers are mapped as type 7 */
 #define KVM_REG_RISCV_ISA_EXT		(0x07 << KVM_REG_RISCV_TYPE_SHIFT)
 
+/* SBI extension registers are mapped as type 8 */
+#define KVM_REG_RISCV_SBI_EXT		(0x08 << KVM_REG_RISCV_TYPE_SHIFT)
+#define KVM_REG_RISCV_SBI_SINGLE	(0x0 << KVM_REG_RISCV_SUBTYPE_SHIFT)
+#define KVM_REG_RISCV_SBI_MULTI_EN	(0x1 << KVM_REG_RISCV_SUBTYPE_SHIFT)
+#define KVM_REG_RISCV_SBI_MULTI_DIS	(0x2 << KVM_REG_RISCV_SUBTYPE_SHIFT)
+#define KVM_REG_RISCV_SBI_MULTI_REG(__ext_id)	\
+		((__ext_id) / __BITS_PER_LONG)
+#define KVM_REG_RISCV_SBI_MULTI_MASK(__ext_id)	\
+		(1UL << ((__ext_id) % __BITS_PER_LONG))
+#define KVM_REG_RISCV_SBI_MULTI_REG_LAST	\
+		KVM_REG_RISCV_SBI_MULTI_REG(KVM_RISCV_SBI_EXT_MAX - 1)
+
 #endif
 
 #endif /* __LINUX_KVM_RISCV_H */
diff --git a/linux-headers/asm-riscv/unistd.h b/linux-headers/asm-riscv/unistd.h
index 73d7cdd2ec..950ab3fd44 100644
--- a/linux-headers/asm-riscv/unistd.h
+++ b/linux-headers/asm-riscv/unistd.h
@@ -43,3 +43,12 @@
 #define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15)
 #endif
 __SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache)
+
+/*
+ * Allows userspace to query the kernel for CPU architecture and
+ * microarchitecture details across a given set of CPUs.
+ */
+#ifndef __NR_riscv_hwprobe
+#define __NR_riscv_hwprobe (__NR_arch_specific_syscall + 14)
+#endif
+__SYSCALL(__NR_riscv_hwprobe, sys_riscv_hwprobe)
diff --git a/linux-headers/asm-s390/unistd_32.h b/linux-headers/asm-s390/unistd_32.h
index 8e644d65f5..800f3adb20 100644
--- a/linux-headers/asm-s390/unistd_32.h
+++ b/linux-headers/asm-s390/unistd_32.h
@@ -419,6 +419,7 @@
 #define __NR_landlock_create_ruleset 444
 #define __NR_landlock_add_rule 445
 #define __NR_landlock_restrict_self 446
+#define __NR_memfd_secret 447
 #define __NR_process_mrelease 448
 #define __NR_futex_waitv 449
 #define __NR_set_mempolicy_home_node 450
diff --git a/linux-headers/asm-s390/unistd_64.h b/linux-headers/asm-s390/unistd_64.h
index 51da542fec..399a605901 100644
--- a/linux-headers/asm-s390/unistd_64.h
+++ b/linux-headers/asm-s390/unistd_64.h
@@ -367,6 +367,7 @@
 #define __NR_landlock_create_ruleset 444
 #define __NR_landlock_add_rule 445
 #define __NR_landlock_restrict_self 446
+#define __NR_memfd_secret 447
 #define __NR_process_mrelease 448
 #define __NR_futex_waitv 449
 #define __NR_set_mempolicy_home_node 450
diff --git a/linux-headers/asm-x86/kvm.h b/linux-headers/asm-x86/kvm.h
index 2937e7bf69..2b3a8f7bd2 100644
--- a/linux-headers/asm-x86/kvm.h
+++ b/linux-headers/asm-x86/kvm.h
@@ -557,4 +557,7 @@ struct kvm_pmu_event_filter {
 #define KVM_VCPU_TSC_CTRL 0 /* control group for the timestamp counter (TSC) */
 #define   KVM_VCPU_TSC_OFFSET 0 /* attribute for the TSC offset */
 
+/* x86-specific KVM_EXIT_HYPERCALL flags. */
+#define KVM_EXIT_HYPERCALL_LONG_MODE	BIT(0)
+
 #endif /* _ASM_X86_KVM_H */
diff --git a/linux-headers/linux/const.h b/linux-headers/linux/const.h
index 5e48987251..1eb84b5087 100644
--- a/linux-headers/linux/const.h
+++ b/linux-headers/linux/const.h
@@ -28,7 +28,7 @@
 #define _BITUL(x)	(_UL(1) << (x))
 #define _BITULL(x)	(_ULL(1) << (x))
 
-#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
+#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1)
 #define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
 
 #define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 599de3c6e3..65b145b317 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -341,8 +341,11 @@ struct kvm_run {
 			__u64 nr;
 			__u64 args[6];
 			__u64 ret;
-			__u32 longmode;
-			__u32 pad;
+
+			union {
+				__u32 longmode;
+				__u64 flags;
+			};
 		} hypercall;
 		/* KVM_EXIT_TPR_ACCESS */
 		struct {
@@ -1182,6 +1185,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_S390_PROTECTED_ASYNC_DISABLE 224
 #define KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP 225
 #define KVM_CAP_PMU_EVENT_MASKED_EVENTS 226
+#define KVM_CAP_COUNTER_OFFSET 227
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -1449,7 +1453,7 @@ struct kvm_vfio_spapr_tce {
 #define KVM_CREATE_VCPU           _IO(KVMIO,   0x41)
 #define KVM_GET_DIRTY_LOG         _IOW(KVMIO,  0x42, struct kvm_dirty_log)
 #define KVM_SET_NR_MMU_PAGES      _IO(KVMIO,   0x44)
-#define KVM_GET_NR_MMU_PAGES      _IO(KVMIO,   0x45)
+#define KVM_GET_NR_MMU_PAGES      _IO(KVMIO,   0x45)  /* deprecated */
 #define KVM_SET_USER_MEMORY_REGION _IOW(KVMIO, 0x46, \
 					struct kvm_userspace_memory_region)
 #define KVM_SET_TSS_ADDR          _IO(KVMIO,   0x47)
@@ -1541,6 +1545,8 @@ struct kvm_s390_ucas_mapping {
 #define KVM_SET_PMU_EVENT_FILTER  _IOW(KVMIO,  0xb2, struct kvm_pmu_event_filter)
 #define KVM_PPC_SVM_OFF		  _IO(KVMIO,  0xb3)
 #define KVM_ARM_MTE_COPY_TAGS	  _IOR(KVMIO,  0xb4, struct kvm_arm_copy_mte_tags)
+/* Available with KVM_CAP_COUNTER_OFFSET */
+#define KVM_ARM_SET_COUNTER_OFFSET _IOW(KVMIO,  0xb5, struct kvm_arm_counter_offset)
 
 /* ioctl for vm fd */
 #define KVM_CREATE_DEVICE	  _IOWR(KVMIO,  0xe0, struct kvm_create_device)
diff --git a/linux-headers/linux/psp-sev.h b/linux-headers/linux/psp-sev.h
index 51d8b3940e..12ccb70099 100644
--- a/linux-headers/linux/psp-sev.h
+++ b/linux-headers/linux/psp-sev.h
@@ -36,6 +36,13 @@ enum {
  * SEV Firmware status code
  */
 typedef enum {
+	/*
+	 * This error code is not in the SEV spec. Its purpose is to convey that
+	 * there was an error that prevented the SEV firmware from being called.
+	 * The SEV API error codes are 16 bits, so the -1 value will not overlap
+	 * with possible values from the specification.
+	 */
+	SEV_RET_NO_FW_CALL = -1,
 	SEV_RET_SUCCESS = 0,
 	SEV_RET_INVALID_PLATFORM_STATE,
 	SEV_RET_INVALID_GUEST_STATE,
diff --git a/linux-headers/linux/userfaultfd.h b/linux-headers/linux/userfaultfd.h
index ba5d0df52f..14e402263a 100644
--- a/linux-headers/linux/userfaultfd.h
+++ b/linux-headers/linux/userfaultfd.h
@@ -38,7 +38,8 @@
 			   UFFD_FEATURE_MINOR_HUGETLBFS |	\
 			   UFFD_FEATURE_MINOR_SHMEM |		\
 			   UFFD_FEATURE_EXACT_ADDRESS |		\
-			   UFFD_FEATURE_WP_HUGETLBFS_SHMEM)
+			   UFFD_FEATURE_WP_HUGETLBFS_SHMEM |	\
+			   UFFD_FEATURE_WP_UNPOPULATED)
 #define UFFD_API_IOCTLS				\
 	((__u64)1 << _UFFDIO_REGISTER |		\
 	 (__u64)1 << _UFFDIO_UNREGISTER |	\
@@ -203,6 +204,12 @@ struct uffdio_api {
 	 *
 	 * UFFD_FEATURE_WP_HUGETLBFS_SHMEM indicates that userfaultfd
 	 * write-protection mode is supported on both shmem and hugetlbfs.
+	 *
+	 * UFFD_FEATURE_WP_UNPOPULATED indicates that userfaultfd
+	 * write-protection mode will always apply to unpopulated pages
+	 * (i.e. empty ptes).  This will be the default behavior for shmem
+	 * & hugetlbfs, so this flag only affects anonymous memory behavior
+	 * when userfault write-protection mode is registered.
 	 */
 #define UFFD_FEATURE_PAGEFAULT_FLAG_WP		(1<<0)
 #define UFFD_FEATURE_EVENT_FORK			(1<<1)
@@ -217,6 +224,7 @@ struct uffdio_api {
 #define UFFD_FEATURE_MINOR_SHMEM		(1<<10)
 #define UFFD_FEATURE_EXACT_ADDRESS		(1<<11)
 #define UFFD_FEATURE_WP_HUGETLBFS_SHMEM		(1<<12)
+#define UFFD_FEATURE_WP_UNPOPULATED		(1<<13)
 	__u64 features;
 
 	__u64 ioctls;
@@ -297,6 +305,13 @@ struct uffdio_writeprotect {
 struct uffdio_continue {
 	struct uffdio_range range;
 #define UFFDIO_CONTINUE_MODE_DONTWAKE		((__u64)1<<0)
+	/*
+	 * UFFDIO_CONTINUE_MODE_WP will map the page write protected on
+	 * the fly.  UFFDIO_CONTINUE_MODE_WP is available only if the
+	 * write protected ioctl is implemented for the range
+	 * according to the uffdio_register.ioctls.
+	 */
+#define UFFDIO_CONTINUE_MODE_WP			((__u64)1<<1)
 	__u64 mode;
 
 	/*
-- 
2.41.0

[PATCH v7 10/20] target/riscv/kvm.c: init 'misa_ext_mask' with scratch CPU

[Daniel Henrique Barboza]

At this moment we're retrieving env->misa_ext during
kvm_arch_init_cpu(), leaving env->misa_ext_mask behind.

We want to set env->misa_ext_mask, and we want to set it as early as
possible. The reason is that we're going to use it in the validation
process of the KVM MISA properties we're going to add next. Setting it
during arch_init_cpu() is too late for user validation.

Move the code to a new helper that is going to be called during init()
time, via kvm_riscv_init_user_properties(), like we're already doing for
the machine ID properties. Set both misa_ext and misa_ext_mask to the
same value retrieved by the 'isa' config reg.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/kvm.c | 34 +++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 602727cdfd..4d0808cb9a 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -396,6 +396,28 @@ static void kvm_riscv_init_machine_ids(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
     }
 }
 
+static void kvm_riscv_init_misa_ext_mask(RISCVCPU *cpu,
+                                         KVMScratchCPU *kvmcpu)
+{
+    CPURISCVState *env = &cpu->env;
+    struct kvm_one_reg reg;
+    int ret;
+
+    reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                              KVM_REG_RISCV_CONFIG_REG(isa));
+    reg.addr = (uint64_t)&env->misa_ext_mask;
+    ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
+
+    if (ret) {
+        error_report("Unable to fetch ISA register from KVM, "
+                     "error %d", ret);
+        kvm_riscv_destroy_scratch_vcpu(kvmcpu);
+        exit(EXIT_FAILURE);
+    }
+
+    env->misa_ext = env->misa_ext_mask;
+}
+
 void kvm_riscv_init_user_properties(Object *cpu_obj)
 {
     RISCVCPU *cpu = RISCV_CPU(cpu_obj);
@@ -406,6 +428,7 @@ void kvm_riscv_init_user_properties(Object *cpu_obj)
     }
 
     kvm_riscv_init_machine_ids(cpu, &kvmcpu);
+    kvm_riscv_init_misa_ext_mask(cpu, &kvmcpu);
 
     kvm_riscv_destroy_scratch_vcpu(&kvmcpu);
 }
@@ -525,21 +548,10 @@ static int kvm_vcpu_set_machine_ids(RISCVCPU *cpu, CPUState *cs)
 int kvm_arch_init_vcpu(CPUState *cs)
 {
     int ret = 0;
-    target_ulong isa;
     RISCVCPU *cpu = RISCV_CPU(cs);
-    CPURISCVState *env = &cpu->env;
-    uint64_t id;
 
     qemu_add_vm_change_state_handler(kvm_riscv_vm_state_change, cs);
 
-    id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
-                          KVM_REG_RISCV_CONFIG_REG(isa));
-    ret = kvm_get_one_reg(cs, id, &isa);
-    if (ret) {
-        return ret;
-    }
-    env->misa_ext = isa;
-
     if (!object_dynamic_cast(OBJECT(cpu), TYPE_RISCV_CPU_HOST)) {
         ret = kvm_vcpu_set_machine_ids(cpu, cs);
     }
-- 
2.41.0

[PATCH v7 11/20] target/riscv/cpu: add misa_ext_info_arr[]

[Daniel Henrique Barboza]

Next patch will add KVM specific user properties for both MISA and
multi-letter extensions. For MISA extensions we want to make use of what
is already available in misa_ext_cfgs[] to avoid code repetition.

misa_ext_info_arr[] array will hold name and description for each MISA
extension that misa_ext_cfgs[] is declaring. We'll then use this new
array in KVM code to avoid duplicating strings. Two getters were added
to allow KVM to retrieve the 'name' and 'description' for each MISA
property.

There's nothing holding us back from doing the same with multi-letter
extensions. For now doing just with MISA extensions is enough.

It is worth documenting that even using the __bultin_ctz() directive to
populate the misa_ext_info_arr[] we are forced to assign 'name' and
'description' during runtime in riscv_cpu_add_misa_properties(). The
reason is that some Gitlab runners ('clang-user' and 'tsan-build') will
throw errors like this if we fetch 'name' and 'description' from the
array in the MISA_CFG() macro:

../target/riscv/cpu.c:1624:5: error: initializer element is not a
                              compile-time constant
    MISA_CFG(RVA, true),
    ^~~~~~~~~~~~~~~~~~~
../target/riscv/cpu.c:1619:53: note: expanded from macro 'MISA_CFG'
    {.name = misa_ext_info_arr[MISA_INFO_IDX(_bit)].name, \
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

gcc and others compilers/builders were fine with that change. We can't
ignore failures in the Gitlab pipeline though, so code was changed to
make every runner happy.

As a side effect, misa_ext_cfg[] is no longer a 'const' array because
it must be set during runtime.

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 110 +++++++++++++++++++++++++++++++++------------
 target/riscv/cpu.h |   7 ++-
 2 files changed, 88 insertions(+), 29 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 58439a05d1..c1693d5e9c 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1558,33 +1558,83 @@ static void cpu_get_misa_ext_cfg(Object *obj, Visitor *v, const char *name,
     visit_type_bool(v, name, &value, errp);
 }
 
-static const RISCVCPUMisaExtConfig misa_ext_cfgs[] = {
-    {.name = "a", .description = "Atomic instructions",
-     .misa_bit = RVA, .enabled = true},
-    {.name = "c", .description = "Compressed instructions",
-     .misa_bit = RVC, .enabled = true},
-    {.name = "d", .description = "Double-precision float point",
-     .misa_bit = RVD, .enabled = true},
-    {.name = "f", .description = "Single-precision float point",
-     .misa_bit = RVF, .enabled = true},
-    {.name = "i", .description = "Base integer instruction set",
-     .misa_bit = RVI, .enabled = true},
-    {.name = "e", .description = "Base integer instruction set (embedded)",
-     .misa_bit = RVE, .enabled = false},
-    {.name = "m", .description = "Integer multiplication and division",
-     .misa_bit = RVM, .enabled = true},
-    {.name = "s", .description = "Supervisor-level instructions",
-     .misa_bit = RVS, .enabled = true},
-    {.name = "u", .description = "User-level instructions",
-     .misa_bit = RVU, .enabled = true},
-    {.name = "h", .description = "Hypervisor",
-     .misa_bit = RVH, .enabled = true},
-    {.name = "x-j", .description = "Dynamic translated languages",
-     .misa_bit = RVJ, .enabled = false},
-    {.name = "v", .description = "Vector operations",
-     .misa_bit = RVV, .enabled = false},
-    {.name = "g", .description = "General purpose (IMAFD_Zicsr_Zifencei)",
-     .misa_bit = RVG, .enabled = false},
+typedef struct misa_ext_info {
+    const char *name;
+    const char *description;
+} MISAExtInfo;
+
+#define MISA_INFO_IDX(_bit) \
+    __builtin_ctz(_bit)
+
+#define MISA_EXT_INFO(_bit, _propname, _descr) \
+    [MISA_INFO_IDX(_bit)] = {.name = _propname, .description = _descr}
+
+static const MISAExtInfo misa_ext_info_arr[] = {
+    MISA_EXT_INFO(RVA, "a", "Atomic instructions"),
+    MISA_EXT_INFO(RVC, "c", "Compressed instructions"),
+    MISA_EXT_INFO(RVD, "d", "Double-precision float point"),
+    MISA_EXT_INFO(RVF, "f", "Single-precision float point"),
+    MISA_EXT_INFO(RVI, "i", "Base integer instruction set"),
+    MISA_EXT_INFO(RVE, "e", "Base integer instruction set (embedded)"),
+    MISA_EXT_INFO(RVM, "m", "Integer multiplication and division"),
+    MISA_EXT_INFO(RVS, "s", "Supervisor-level instructions"),
+    MISA_EXT_INFO(RVU, "u", "User-level instructions"),
+    MISA_EXT_INFO(RVH, "h", "Hypervisor"),
+    MISA_EXT_INFO(RVJ, "x-j", "Dynamic translated languages"),
+    MISA_EXT_INFO(RVV, "v", "Vector operations"),
+    MISA_EXT_INFO(RVG, "g", "General purpose (IMAFD_Zicsr_Zifencei)"),
+};
+
+static int riscv_validate_misa_info_idx(uint32_t bit)
+{
+    int idx;
+
+    /*
+     * Our lowest valid input (RVA) is 1 and
+     * __builtin_ctz() is UB with zero.
+     */
+    g_assert(bit != 0);
+    idx = MISA_INFO_IDX(bit);
+
+    g_assert(idx < ARRAY_SIZE(misa_ext_info_arr));
+    return idx;
+}
+
+const char *riscv_get_misa_ext_name(uint32_t bit)
+{
+    int idx = riscv_validate_misa_info_idx(bit);
+    const char *val = misa_ext_info_arr[idx].name;
+
+    g_assert(val != NULL);
+    return val;
+}
+
+const char *riscv_get_misa_ext_description(uint32_t bit)
+{
+    int idx = riscv_validate_misa_info_idx(bit);
+    const char *val = misa_ext_info_arr[idx].description;
+
+    g_assert(val != NULL);
+    return val;
+}
+
+#define MISA_CFG(_bit, _enabled) \
+    {.misa_bit = _bit, .enabled = _enabled}
+
+static RISCVCPUMisaExtConfig misa_ext_cfgs[] = {
+    MISA_CFG(RVA, true),
+    MISA_CFG(RVC, true),
+    MISA_CFG(RVD, true),
+    MISA_CFG(RVF, true),
+    MISA_CFG(RVI, true),
+    MISA_CFG(RVE, false),
+    MISA_CFG(RVM, true),
+    MISA_CFG(RVS, true),
+    MISA_CFG(RVU, true),
+    MISA_CFG(RVH, true),
+    MISA_CFG(RVJ, false),
+    MISA_CFG(RVV, false),
+    MISA_CFG(RVG, false),
 };
 
 static void riscv_cpu_add_misa_properties(Object *cpu_obj)
@@ -1592,7 +1642,11 @@ static void riscv_cpu_add_misa_properties(Object *cpu_obj)
     int i;
 
     for (i = 0; i < ARRAY_SIZE(misa_ext_cfgs); i++) {
-        const RISCVCPUMisaExtConfig *misa_cfg = &misa_ext_cfgs[i];
+        RISCVCPUMisaExtConfig *misa_cfg = &misa_ext_cfgs[i];
+        int bit = misa_cfg->misa_bit;
+
+        misa_cfg->name = riscv_get_misa_ext_name(bit);
+        misa_cfg->description = riscv_get_misa_ext_description(bit);
 
         object_property_add(cpu_obj, misa_cfg->name, "bool",
                             cpu_get_misa_ext_cfg,
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index cc20ee25a7..9830ec5f75 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -41,7 +41,10 @@
 
 #define RV(x) ((target_ulong)1 << (x - 'A'))
 
-/* Consider updating misa_ext_cfgs[] when adding new MISA bits here */
+/*
+ * Consider updating misa_ext_info_arr[] and misa_ext_cfgs[]
+ * when adding new MISA bits here.
+ */
 #define RVI RV('I')
 #define RVE RV('E') /* E and I are mutually exclusive */
 #define RVM RV('M')
@@ -56,6 +59,8 @@
 #define RVJ RV('J')
 #define RVG RV('G')
 
+const char *riscv_get_misa_ext_name(uint32_t bit);
+const char *riscv_get_misa_ext_description(uint32_t bit);
 
 /* Privileged specification version */
 enum {
-- 
2.41.0

[PATCH v7 12/20] target/riscv: add KVM specific MISA properties

[Daniel Henrique Barboza]

Using all TCG user properties in KVM is tricky. First because KVM
supports only a small subset of what TCG provides, so most of the
cpu->cfg flags do nothing for KVM.

Second, and more important, we don't have a way of telling if any given
value is an user input or not. For TCG this has a small impact since we
just validating everything and error out if needed. But for KVM it would
be good to know if a given value was set by the user or if it's a value
already provided by KVM. Otherwise we don't know how to handle failed
kvm_set_one_regs() when writing the configurations back.

These characteristics make it overly complicated to use the same user
facing flags for both KVM and TCG. A simpler approach is to create KVM
specific properties that have specialized logic, forking KVM and TCG use
cases for those cases only. Fully separating KVM/TCG properties is
unneeded at this point - in fact we want the user experience to be as
equal as possible, regardless of the acceleration chosen.

We'll start this fork with the MISA properties, adding the MISA bits
that the KVM driver currently supports. A new KVMCPUConfig type is
introduced. It'll hold general information about an extension. For MISA
extensions we're going to use the newly created getters of
misa_ext_infos[] to populate their name and description. 'offset' holds
the MISA bit (RVA, RVC, ...). We're calling it 'offset' instead of
'misa_bit' because this same KVMCPUConfig struct will be used to
multi-letter extensions later on.

This new type also holds a 'user_set' flag. This flag will be set when
the user set an option that's different than what is already configured
in the host, requiring KVM intervention to write the regs back during
kvm_arch_init_vcpu(). Similar mechanics will be implemented for
multi-letter extensions as well.

There is no need to duplicate more code than necessary, so we're going
to use the existing kvm_riscv_init_user_properties() to add the KVM
specific properties. Any code that is adding a TCG user prop is then
changed slightly to verify first if there's a KVM prop with the same
name already added.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c |  5 +++
 target/riscv/kvm.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index c1693d5e9c..a9df61c9b4 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1648,6 +1648,11 @@ static void riscv_cpu_add_misa_properties(Object *cpu_obj)
         misa_cfg->name = riscv_get_misa_ext_name(bit);
         misa_cfg->description = riscv_get_misa_ext_description(bit);
 
+        /* Check if KVM already created the property */
+        if (object_property_find(cpu_obj, misa_cfg->name)) {
+            continue;
+        }
+
         object_property_add(cpu_obj, misa_cfg->name, "bool",
                             cpu_get_misa_ext_cfg,
                             cpu_set_misa_ext_cfg,
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 4d0808cb9a..c55d0ec7ab 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -22,8 +22,10 @@
 #include <linux/kvm.h>
 
 #include "qemu/timer.h"
+#include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
+#include "qapi/visitor.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
 #include "sysemu/kvm_int.h"
@@ -105,6 +107,81 @@ static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
         } \
     } while (0)
 
+typedef struct KVMCPUConfig {
+    const char *name;
+    const char *description;
+    target_ulong offset;
+    int kvm_reg_id;
+    bool user_set;
+} KVMCPUConfig;
+
+#define KVM_MISA_CFG(_bit, _reg_id) \
+    {.offset = _bit, .kvm_reg_id = _reg_id}
+
+/* KVM ISA extensions */
+static KVMCPUConfig kvm_misa_ext_cfgs[] = {
+    KVM_MISA_CFG(RVA, KVM_RISCV_ISA_EXT_A),
+    KVM_MISA_CFG(RVC, KVM_RISCV_ISA_EXT_C),
+    KVM_MISA_CFG(RVD, KVM_RISCV_ISA_EXT_D),
+    KVM_MISA_CFG(RVF, KVM_RISCV_ISA_EXT_F),
+    KVM_MISA_CFG(RVH, KVM_RISCV_ISA_EXT_H),
+    KVM_MISA_CFG(RVI, KVM_RISCV_ISA_EXT_I),
+    KVM_MISA_CFG(RVM, KVM_RISCV_ISA_EXT_M),
+};
+
+static void kvm_cpu_set_misa_ext_cfg(Object *obj, Visitor *v,
+                                     const char *name,
+                                     void *opaque, Error **errp)
+{
+    KVMCPUConfig *misa_ext_cfg = opaque;
+    target_ulong misa_bit = misa_ext_cfg->offset;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    CPURISCVState *env = &cpu->env;
+    bool value, host_bit;
+
+    if (!visit_type_bool(v, name, &value, errp)) {
+        return;
+    }
+
+    host_bit = env->misa_ext_mask & misa_bit;
+
+    if (value == host_bit) {
+        return;
+    }
+
+    if (!value) {
+        misa_ext_cfg->user_set = true;
+        return;
+    }
+
+    /*
+     * Forbid users to enable extensions that aren't
+     * available in the hart.
+     */
+    error_setg(errp, "Enabling MISA bit '%s' is not allowed: it's not "
+               "enabled in the host", misa_ext_cfg->name);
+}
+
+static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(kvm_misa_ext_cfgs); i++) {
+        KVMCPUConfig *misa_cfg = &kvm_misa_ext_cfgs[i];
+        int bit = misa_cfg->offset;
+
+        misa_cfg->name = riscv_get_misa_ext_name(bit);
+        misa_cfg->description = riscv_get_misa_ext_description(bit);
+
+        object_property_add(cpu_obj, misa_cfg->name, "bool",
+                            NULL,
+                            kvm_cpu_set_misa_ext_cfg,
+                            NULL, misa_cfg);
+        object_property_set_description(cpu_obj, misa_cfg->name,
+                                        misa_cfg->description);
+    }
+}
+
 static int kvm_riscv_get_regs_core(CPUState *cs)
 {
     int ret = 0;
@@ -427,6 +504,7 @@ void kvm_riscv_init_user_properties(Object *cpu_obj)
         return;
     }
 
+    kvm_riscv_add_cpu_user_properties(cpu_obj);
     kvm_riscv_init_machine_ids(cpu, &kvmcpu);
     kvm_riscv_init_misa_ext_mask(cpu, &kvmcpu);
 
-- 
2.41.0

[PATCH v7 13/20] target/riscv/kvm.c: update KVM MISA bits

[Daniel Henrique Barboza]

Our design philosophy with KVM properties can be resumed in two main
decisions based on KVM interface availability and what the user wants to
do:

- if the user disables an extension that the host KVM module doesn't
know about (i.e. it doesn't implement the kvm_get_one_reg() interface),
keep booting the CPU. This will avoid users having to deal with issues
with older KVM versions while disabling features they don't care;

- for any other case we're going to error out immediately. If the user
wants to enable a feature that KVM doesn't know about this a problem that
is worth aborting - the user must know that the feature wasn't enabled
in the hart. Likewise, if KVM knows about the extension, the user wants
to enable/disable it, and we fail to do it so, that's also a problem we
can't shrug it off.

In the case of MISA bits we won't even try enabling bits that aren't
already available in the host. The ioctl() is so likely to fail that
it's not worth trying. This check is already done in the previous patch,
in kvm_cpu_set_misa_ext_cfg(), thus we don't need to worry about it now.

In kvm_riscv_update_cpu_misa_ext() we'll go through every potential user
option and do as follows:

- if the user didn't set the property or set to the same value of the
host, do nothing;

- Disable the given extension in KVM. Error out if anything goes wrong.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/kvm.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index c55d0ec7ab..7afd6024e6 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -162,6 +162,41 @@ static void kvm_cpu_set_misa_ext_cfg(Object *obj, Visitor *v,
                "enabled in the host", misa_ext_cfg->name);
 }
 
+static void kvm_riscv_update_cpu_misa_ext(RISCVCPU *cpu, CPUState *cs)
+{
+    CPURISCVState *env = &cpu->env;
+    uint64_t id, reg;
+    int i, ret;
+
+    for (i = 0; i < ARRAY_SIZE(kvm_misa_ext_cfgs); i++) {
+        KVMCPUConfig *misa_cfg = &kvm_misa_ext_cfgs[i];
+        target_ulong misa_bit = misa_cfg->offset;
+
+        if (!misa_cfg->user_set) {
+            continue;
+        }
+
+        /* If we're here we're going to disable the MISA bit */
+        reg = 0;
+        id = kvm_riscv_reg_id(env, KVM_REG_RISCV_ISA_EXT,
+                              misa_cfg->kvm_reg_id);
+        ret = kvm_set_one_reg(cs, id, &reg);
+        if (ret != 0) {
+            /*
+             * We're not checking for -EINVAL because if the bit is about
+             * to be disabled, it means that it was already enabled by
+             * KVM. We determined that by fetching the 'isa' register
+             * during init() time. Any error at this point is worth
+             * aborting.
+             */
+            error_report("Unable to set KVM reg %s, error %d",
+                         misa_cfg->name, ret);
+            exit(EXIT_FAILURE);
+        }
+        env->misa_ext &= ~misa_bit;
+    }
+}
+
 static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
 {
     int i;
@@ -632,8 +667,13 @@ int kvm_arch_init_vcpu(CPUState *cs)
 
     if (!object_dynamic_cast(OBJECT(cpu), TYPE_RISCV_CPU_HOST)) {
         ret = kvm_vcpu_set_machine_ids(cpu, cs);
+        if (ret != 0) {
+            return ret;
+        }
     }
 
+    kvm_riscv_update_cpu_misa_ext(cpu, cs);
+
     return ret;
 }
 
-- 
2.41.0

[PATCH v7 14/20] target/riscv/kvm.c: add multi-letter extension KVM properties

[Daniel Henrique Barboza]

Let's add KVM user properties for the multi-letter extensions that KVM
currently supports: zicbom, zicboz, zihintpause, zbb, ssaia, sstc,
svinval and svpbmt.

As with MISA extensions, we're using the KVMCPUConfig type to hold
information about the state of each extension. However, multi-letter
extensions have more cases to cover than MISA extensions, so we're
adding an extra 'supported' flag as well. This flag will reflect if a
given extension is supported by KVM, i.e. KVM knows how to handle it.
This is determined during KVM extension discovery in
kvm_riscv_init_multiext_cfg(), where we test for EINVAL errors. Any
other error different from EINVAL will cause an abort.

The use of the 'user_set' is similar to what we already do with MISA
extensions: the flag set only if the user is changing the extension
state.

The 'supported' flag will be used later on to make an exception for
users that are disabling multi-letter extensions that are unknown to
KVM.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/cpu.c |   8 +++
 target/riscv/kvm.c | 119 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 127 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index a9df61c9b4..f348424170 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1778,6 +1778,14 @@ static void riscv_cpu_add_user_properties(Object *obj)
     riscv_cpu_add_misa_properties(obj);
 
     for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
+#ifndef CONFIG_USER_ONLY
+        if (kvm_enabled()) {
+            /* Check if KVM created the property already */
+            if (object_property_find(obj, prop->name)) {
+                continue;
+            }
+        }
+#endif
         qdev_property_add_static(dev, prop);
     }
 
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 7afd6024e6..6ef81a6825 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -113,6 +113,7 @@ typedef struct KVMCPUConfig {
     target_ulong offset;
     int kvm_reg_id;
     bool user_set;
+    bool supported;
 } KVMCPUConfig;
 
 #define KVM_MISA_CFG(_bit, _reg_id) \
@@ -197,6 +198,81 @@ static void kvm_riscv_update_cpu_misa_ext(RISCVCPU *cpu, CPUState *cs)
     }
 }
 
+#define CPUCFG(_prop) offsetof(struct RISCVCPUConfig, _prop)
+
+#define KVM_EXT_CFG(_name, _prop, _reg_id) \
+    {.name = _name, .offset = CPUCFG(_prop), \
+     .kvm_reg_id = _reg_id}
+
+static KVMCPUConfig kvm_multi_ext_cfgs[] = {
+    KVM_EXT_CFG("zicbom", ext_icbom, KVM_RISCV_ISA_EXT_ZICBOM),
+    KVM_EXT_CFG("zicboz", ext_icboz, KVM_RISCV_ISA_EXT_ZICBOZ),
+    KVM_EXT_CFG("zihintpause", ext_zihintpause, KVM_RISCV_ISA_EXT_ZIHINTPAUSE),
+    KVM_EXT_CFG("zbb", ext_zbb, KVM_RISCV_ISA_EXT_ZBB),
+    KVM_EXT_CFG("ssaia", ext_ssaia, KVM_RISCV_ISA_EXT_SSAIA),
+    KVM_EXT_CFG("sstc", ext_sstc, KVM_RISCV_ISA_EXT_SSTC),
+    KVM_EXT_CFG("svinval", ext_svinval, KVM_RISCV_ISA_EXT_SVINVAL),
+    KVM_EXT_CFG("svpbmt", ext_svpbmt, KVM_RISCV_ISA_EXT_SVPBMT),
+};
+
+static void kvm_cpu_cfg_set(RISCVCPU *cpu, KVMCPUConfig *multi_ext,
+                            uint32_t val)
+{
+    int cpu_cfg_offset = multi_ext->offset;
+    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
+
+    *ext_enabled = val;
+}
+
+static uint32_t kvm_cpu_cfg_get(RISCVCPU *cpu,
+                                KVMCPUConfig *multi_ext)
+{
+    int cpu_cfg_offset = multi_ext->offset;
+    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
+
+    return *ext_enabled;
+}
+
+static void kvm_cpu_set_multi_ext_cfg(Object *obj, Visitor *v,
+                                      const char *name,
+                                      void *opaque, Error **errp)
+{
+    KVMCPUConfig *multi_ext_cfg = opaque;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    bool value, host_val;
+
+    if (!visit_type_bool(v, name, &value, errp)) {
+        return;
+    }
+
+    host_val = kvm_cpu_cfg_get(cpu, multi_ext_cfg);
+
+    /*
+     * Ignore if the user is setting the same value
+     * as the host.
+     */
+    if (value == host_val) {
+        return;
+    }
+
+    if (!multi_ext_cfg->supported) {
+        /*
+         * Error out if the user is trying to enable an
+         * extension that KVM doesn't support. Ignore
+         * option otherwise.
+         */
+        if (value) {
+            error_setg(errp, "KVM does not support disabling extension %s",
+                       multi_ext_cfg->name);
+        }
+
+        return;
+    }
+
+    multi_ext_cfg->user_set = true;
+    kvm_cpu_cfg_set(cpu, multi_ext_cfg, value);
+}
+
 static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
 {
     int i;
@@ -215,6 +291,15 @@ static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
         object_property_set_description(cpu_obj, misa_cfg->name,
                                         misa_cfg->description);
     }
+
+    for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) {
+        KVMCPUConfig *multi_cfg = &kvm_multi_ext_cfgs[i];
+
+        object_property_add(cpu_obj, multi_cfg->name, "bool",
+                            NULL,
+                            kvm_cpu_set_multi_ext_cfg,
+                            NULL, multi_cfg);
+    }
 }
 
 static int kvm_riscv_get_regs_core(CPUState *cs)
@@ -530,6 +615,39 @@ static void kvm_riscv_init_misa_ext_mask(RISCVCPU *cpu,
     env->misa_ext = env->misa_ext_mask;
 }
 
+static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
+{
+    CPURISCVState *env = &cpu->env;
+    uint64_t val;
+    int i, ret;
+
+    for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) {
+        KVMCPUConfig *multi_ext_cfg = &kvm_multi_ext_cfgs[i];
+        struct kvm_one_reg reg;
+
+        reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_ISA_EXT,
+                                  multi_ext_cfg->kvm_reg_id);
+        reg.addr = (uint64_t)&val;
+        ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
+        if (ret != 0) {
+            if (ret == -EINVAL) {
+                /* Silently default to 'false' if KVM does not support it. */
+                multi_ext_cfg->supported = false;
+                val = false;
+            } else {
+                error_report("Unable to read ISA_EXT KVM register %s, "
+                             "error %d", multi_ext_cfg->name, ret);
+                kvm_riscv_destroy_scratch_vcpu(kvmcpu);
+                exit(EXIT_FAILURE);
+            }
+        } else {
+            multi_ext_cfg->supported = true;
+        }
+
+        kvm_cpu_cfg_set(cpu, multi_ext_cfg, val);
+    }
+}
+
 void kvm_riscv_init_user_properties(Object *cpu_obj)
 {
     RISCVCPU *cpu = RISCV_CPU(cpu_obj);
@@ -542,6 +660,7 @@ void kvm_riscv_init_user_properties(Object *cpu_obj)
     kvm_riscv_add_cpu_user_properties(cpu_obj);
     kvm_riscv_init_machine_ids(cpu, &kvmcpu);
     kvm_riscv_init_misa_ext_mask(cpu, &kvmcpu);
+    kvm_riscv_init_multiext_cfg(cpu, &kvmcpu);
 
     kvm_riscv_destroy_scratch_vcpu(&kvmcpu);
 }
-- 
2.41.0

[PATCH v7 15/20] target/riscv/cpu.c: add satp_mode properties earlier

[Daniel Henrique Barboza]

riscv_cpu_add_user_properties() ended up with an excess of "#ifndef
CONFIG_USER_ONLY" blocks after changes that added KVM properties
handling.

KVM specific properties are required to be created earlier than their
TCG counterparts, but the remaining props can be created at any order.
Move riscv_add_satp_mode_properties() to the start of the function,
inside the !CONFIG_USER_ONLY block already present there, to remove the
last ifndef block.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 target/riscv/cpu.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index f348424170..db718eff65 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1770,6 +1770,8 @@ static void riscv_cpu_add_user_properties(Object *obj)
     DeviceState *dev = DEVICE(obj);
 
 #ifndef CONFIG_USER_ONLY
+    riscv_add_satp_mode_properties(obj);
+
     if (kvm_enabled()) {
         kvm_riscv_init_user_properties(obj);
     }
@@ -1788,10 +1790,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
 #endif
         qdev_property_add_static(dev, prop);
     }
-
-#ifndef CONFIG_USER_ONLY
-    riscv_add_satp_mode_properties(obj);
-#endif
 }
 
 static Property riscv_cpu_properties[] = {
-- 
2.41.0

[PATCH v7 16/20] target/riscv/cpu.c: remove priv_ver check from riscv_isa_string_ext()

[Daniel Henrique Barboza]

riscv_isa_string_ext() is being used by riscv_isa_string(), which is
then used by boards to retrieve the 'riscv,isa' string to be written in
the FDT. All this happens after riscv_cpu_realize(), meaning that we're
already past riscv_cpu_validate_set_extensions() and, more important,
riscv_cpu_disable_priv_spec_isa_exts().

This means that all extensions that needed to be disabled due to
priv_spec mismatch are already disabled. Checking this again during
riscv_isa_string_ext() is unneeded. Remove it.

As a bonus, riscv_isa_string_ext() can now be used with the 'host'
KVM-only CPU type since it doesn't have a env->priv_ver assigned and it
would fail this check for no good reason.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/cpu.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index db718eff65..6cdcbaac30 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -2042,8 +2042,7 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char **isa_str,
     int i;
 
     for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) {
-        if (cpu->env.priv_ver >= isa_edata_arr[i].min_version &&
-            isa_ext_is_enabled(cpu, &isa_edata_arr[i])) {
+        if (isa_ext_is_enabled(cpu, &isa_edata_arr[i])) {
             new = g_strconcat(old, "_", isa_edata_arr[i].name, NULL);
             g_free(old);
             old = new;
-- 
2.41.0

[PATCH v7 17/20] target/riscv/cpu.c: create KVM mock properties

[Daniel Henrique Barboza]

KVM-specific properties are being created inside target/riscv/kvm.c. But
at this moment we're gathering all the remaining properties from TCG and
adding them as is when running KVM. This creates a situation where
non-KVM properties are setting flags to 'true' due to its default
settings (e.g.  Zawrs). Users can also freely enable them via command
line.

This doesn't impact runtime per se because KVM doesn't care about these
flags, but code such as riscv_isa_string_ext() take those flags into
account. The result is that, for a KVM guest, setting non-KVM properties
will make them appear in the riscv,isa DT.

We want to keep the same API for both TCG and KVM and at the same time,
when running KVM, forbid non-KVM extensions to be enabled internally. We
accomplish both by changing riscv_cpu_add_user_properties() to add a
mock boolean property for every non-KVM extension in
riscv_cpu_extensions[]. Then, when running KVM, users are still free to
set extensions at will, but we'll error out if a non-KVM extension is
enabled. Setting such extension to 'false' will be ignored.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/cpu.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 6cdcbaac30..9821dfeb43 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1758,6 +1758,26 @@ static Property riscv_cpu_extensions[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
+
+#ifndef CONFIG_USER_ONLY
+static void cpu_set_cfg_unavailable(Object *obj, Visitor *v,
+                                    const char *name,
+                                    void *opaque, Error **errp)
+{
+    const char *propname = opaque;
+    bool value;
+
+    if (!visit_type_bool(v, name, &value, errp)) {
+        return;
+    }
+
+    if (value) {
+        error_setg(errp, "extension %s is not available with KVM",
+                   propname);
+    }
+}
+#endif
+
 /*
  * Add CPU properties with user-facing flags.
  *
@@ -1786,6 +1806,22 @@ static void riscv_cpu_add_user_properties(Object *obj)
             if (object_property_find(obj, prop->name)) {
                 continue;
             }
+
+            /*
+             * Set the default to disabled for every extension
+             * unknown to KVM and error out if the user attempts
+             * to enable any of them.
+             *
+             * We're giving a pass for non-bool properties since they're
+             * not related to the availability of extensions and can be
+             * safely ignored as is.
+             */
+            if (prop->info == &qdev_prop_bool) {
+                object_property_add(obj, prop->name, "bool",
+                                    NULL, cpu_set_cfg_unavailable,
+                                    NULL, (void *)prop->name);
+                continue;
+            }
         }
 #endif
         qdev_property_add_static(dev, prop);
-- 
2.41.0

[PATCH v7 18/20] target/riscv: update multi-letter extension KVM properties

[Daniel Henrique Barboza]

We're now ready to update the multi-letter extensions status for KVM.

kvm_riscv_update_cpu_cfg_isa_ext() is called called during vcpu creation
time to verify which user options changes host defaults (via the 'user_set'
flag) and tries to write them back to KVM.

Failure to commit a change to KVM is only ignored in case KVM doesn't
know about the extension (-EINVAL error code) and the user wanted to
disable the given extension. Otherwise we're going to abort the boot
process.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/kvm.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 6ef81a6825..2edf0270e3 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -273,6 +273,32 @@ static void kvm_cpu_set_multi_ext_cfg(Object *obj, Visitor *v,
     kvm_cpu_cfg_set(cpu, multi_ext_cfg, value);
 }
 
+static void kvm_riscv_update_cpu_cfg_isa_ext(RISCVCPU *cpu, CPUState *cs)
+{
+    CPURISCVState *env = &cpu->env;
+    uint64_t id, reg;
+    int i, ret;
+
+    for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) {
+        KVMCPUConfig *multi_ext_cfg = &kvm_multi_ext_cfgs[i];
+
+        if (!multi_ext_cfg->user_set) {
+            continue;
+        }
+
+        id = kvm_riscv_reg_id(env, KVM_REG_RISCV_ISA_EXT,
+                              multi_ext_cfg->kvm_reg_id);
+        reg = kvm_cpu_cfg_get(cpu, multi_ext_cfg);
+        ret = kvm_set_one_reg(cs, id, &reg);
+        if (ret != 0) {
+            error_report("Unable to %s extension %s in KVM, error %d",
+                         reg ? "enable" : "disable",
+                         multi_ext_cfg->name, ret);
+            exit(EXIT_FAILURE);
+        }
+    }
+}
+
 static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
 {
     int i;
@@ -792,6 +818,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
     }
 
     kvm_riscv_update_cpu_misa_ext(cpu, cs);
+    kvm_riscv_update_cpu_cfg_isa_ext(cpu, cs);
 
     return ret;
 }
-- 
2.41.0

[PATCH v7 19/20] target/riscv/kvm.c: add kvmconfig_get_cfg_addr() helper

[Daniel Henrique Barboza]

There are 2 places in which we need to get a pointer to a certain
property of the cpu->cfg struct based on property offset. Next patch
will add a couple more.

Create a helper to avoid repeating this code over and over.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/kvm.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 2edf0270e3..f048135cd3 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -215,11 +215,15 @@ static KVMCPUConfig kvm_multi_ext_cfgs[] = {
     KVM_EXT_CFG("svpbmt", ext_svpbmt, KVM_RISCV_ISA_EXT_SVPBMT),
 };
 
+static void *kvmconfig_get_cfg_addr(RISCVCPU *cpu, KVMCPUConfig *kvmcfg)
+{
+    return (void *)&cpu->cfg + kvmcfg->offset;
+}
+
 static void kvm_cpu_cfg_set(RISCVCPU *cpu, KVMCPUConfig *multi_ext,
                             uint32_t val)
 {
-    int cpu_cfg_offset = multi_ext->offset;
-    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
+    bool *ext_enabled = kvmconfig_get_cfg_addr(cpu, multi_ext);
 
     *ext_enabled = val;
 }
@@ -227,8 +231,7 @@ static void kvm_cpu_cfg_set(RISCVCPU *cpu, KVMCPUConfig *multi_ext,
 static uint32_t kvm_cpu_cfg_get(RISCVCPU *cpu,
                                 KVMCPUConfig *multi_ext)
 {
-    int cpu_cfg_offset = multi_ext->offset;
-    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
+    bool *ext_enabled = kvmconfig_get_cfg_addr(cpu, multi_ext);
 
     return *ext_enabled;
 }
-- 
2.41.0

[PATCH v7 20/20] target/riscv/kvm.c: read/write (cbom|cboz)_blocksize in KVM

[Daniel Henrique Barboza]

If we don't set a proper cbom_blocksize|cboz_blocksize in the FDT the
Linux Kernel will fail to detect the availability of the CBOM/CBOZ
extensions, regardless of the contents of the 'riscv,isa' DT prop.

The FDT is being written using the cpu->cfg.cbom|z_blocksize attributes,
so let's expose them as user properties like it is already done with
TCG.

This will also require us to determine proper blocksize values during
init() time since the FDT is already created during realize(). We'll
take a ride in kvm_riscv_init_multiext_cfg() to do it. Note that we
don't need to fetch both cbom and cboz blocksizes every time: check for
their parent extensions (icbom and icboz) and only read the blocksizes
if needed.

In contrast with cbom|z_blocksize properties from TCG, the user is not
able to set any value that is different from the 'host' value when
running KVM. KVM can be particularly harsh dealing with it: a ENOTSUPP
can be thrown for the mere attempt of executing kvm_set_one_reg() for
these 2 regs.

Hopefully we don't need to call kvm_set_one_reg() for these regs.
We'll check if the user input matches the host value in
kvm_cpu_set_cbomz_blksize(), the set() accessor for both blocksize
properties. We'll fail fast since it's already known to not be
supported.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/kvm.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index f048135cd3..56d8aa9b17 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -276,6 +276,42 @@ static void kvm_cpu_set_multi_ext_cfg(Object *obj, Visitor *v,
     kvm_cpu_cfg_set(cpu, multi_ext_cfg, value);
 }
 
+static KVMCPUConfig kvm_cbom_blocksize = {
+    .name = "cbom_blocksize",
+    .offset = CPUCFG(cbom_blocksize),
+    .kvm_reg_id = KVM_REG_RISCV_CONFIG_REG(zicbom_block_size)
+};
+
+static KVMCPUConfig kvm_cboz_blocksize = {
+    .name = "cboz_blocksize",
+    .offset = CPUCFG(cboz_blocksize),
+    .kvm_reg_id = KVM_REG_RISCV_CONFIG_REG(zicboz_block_size)
+};
+
+static void kvm_cpu_set_cbomz_blksize(Object *obj, Visitor *v,
+                                      const char *name,
+                                      void *opaque, Error **errp)
+{
+    KVMCPUConfig *cbomz_cfg = opaque;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    uint16_t value, *host_val;
+
+    if (!visit_type_uint16(v, name, &value, errp)) {
+        return;
+    }
+
+    host_val = kvmconfig_get_cfg_addr(cpu, cbomz_cfg);
+
+    if (value != *host_val) {
+        error_report("Unable to set %s to a different value than "
+                     "the host (%u)",
+                     cbomz_cfg->name, *host_val);
+        exit(EXIT_FAILURE);
+    }
+
+    cbomz_cfg->user_set = true;
+}
+
 static void kvm_riscv_update_cpu_cfg_isa_ext(RISCVCPU *cpu, CPUState *cs)
 {
     CPURISCVState *env = &cpu->env;
@@ -329,6 +365,14 @@ static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
                             kvm_cpu_set_multi_ext_cfg,
                             NULL, multi_cfg);
     }
+
+    object_property_add(cpu_obj, "cbom_blocksize", "uint16",
+                        NULL, kvm_cpu_set_cbomz_blksize,
+                        NULL, &kvm_cbom_blocksize);
+
+    object_property_add(cpu_obj, "cboz_blocksize", "uint16",
+                        NULL, kvm_cpu_set_cbomz_blksize,
+                        NULL, &kvm_cboz_blocksize);
 }
 
 static int kvm_riscv_get_regs_core(CPUState *cs)
@@ -644,6 +688,24 @@ static void kvm_riscv_init_misa_ext_mask(RISCVCPU *cpu,
     env->misa_ext = env->misa_ext_mask;
 }
 
+static void kvm_riscv_read_cbomz_blksize(RISCVCPU *cpu, KVMScratchCPU *kvmcpu,
+                                         KVMCPUConfig *cbomz_cfg)
+{
+    CPURISCVState *env = &cpu->env;
+    struct kvm_one_reg reg;
+    int ret;
+
+    reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                              cbomz_cfg->kvm_reg_id);
+    reg.addr = (uint64_t)kvmconfig_get_cfg_addr(cpu, cbomz_cfg);
+    ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
+    if (ret != 0) {
+        error_report("Unable to read KVM reg %s, error %d",
+                     cbomz_cfg->name, ret);
+        exit(EXIT_FAILURE);
+    }
+}
+
 static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
 {
     CPURISCVState *env = &cpu->env;
@@ -675,6 +737,14 @@ static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
 
         kvm_cpu_cfg_set(cpu, multi_ext_cfg, val);
     }
+
+    if (cpu->cfg.ext_icbom) {
+        kvm_riscv_read_cbomz_blksize(cpu, kvmcpu, &kvm_cbom_blocksize);
+    }
+
+    if (cpu->cfg.ext_icboz) {
+        kvm_riscv_read_cbomz_blksize(cpu, kvmcpu, &kvm_cboz_blocksize);
+    }
 }
 
 void kvm_riscv_init_user_properties(Object *cpu_obj)
-- 
2.41.0

Re: [PATCH v7 11/20] target/riscv/cpu: add misa_ext_info_arr[]

[Philippe Mathieu-Daudé]

On 30/6/23 12:08, Daniel Henrique Barboza wrote:
> Next patch will add KVM specific user properties for both MISA and
> multi-letter extensions. For MISA extensions we want to make use of what
> is already available in misa_ext_cfgs[] to avoid code repetition.
> 
> misa_ext_info_arr[] array will hold name and description for each MISA
> extension that misa_ext_cfgs[] is declaring. We'll then use this new
> array in KVM code to avoid duplicating strings. Two getters were added
> to allow KVM to retrieve the 'name' and 'description' for each MISA
> property.
> 
> There's nothing holding us back from doing the same with multi-letter
> extensions. For now doing just with MISA extensions is enough.
> 
> It is worth documenting that even using the __bultin_ctz() directive to
> populate the misa_ext_info_arr[] we are forced to assign 'name' and
> 'description' during runtime in riscv_cpu_add_misa_properties(). The
> reason is that some Gitlab runners ('clang-user' and 'tsan-build') will
> throw errors like this if we fetch 'name' and 'description' from the
> array in the MISA_CFG() macro:
> 
> ../target/riscv/cpu.c:1624:5: error: initializer element is not a
>                                compile-time constant
>      MISA_CFG(RVA, true),
>      ^~~~~~~~~~~~~~~~~~~
> ../target/riscv/cpu.c:1619:53: note: expanded from macro 'MISA_CFG'
>      {.name = misa_ext_info_arr[MISA_INFO_IDX(_bit)].name, \
>               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
> 
> gcc and others compilers/builders were fine with that change. We can't
> ignore failures in the Gitlab pipeline though, so code was changed to
> make every runner happy.
> 
> As a side effect, misa_ext_cfg[] is no longer a 'const' array because
> it must be set during runtime.
> 
> Suggested-by: Andrew Jones <ajones@ventanamicro.com>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/cpu.c | 110 +++++++++++++++++++++++++++++++++------------
>   target/riscv/cpu.h |   7 ++-
>   2 files changed, 88 insertions(+), 29 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v7 11/20] target/riscv/cpu: add misa_ext_info_arr[]

[Andrew Jones]

On Fri, Jun 30, 2023 at 07:08:02AM -0300, Daniel Henrique Barboza wrote:
> Next patch will add KVM specific user properties for both MISA and
> multi-letter extensions. For MISA extensions we want to make use of what
> is already available in misa_ext_cfgs[] to avoid code repetition.
> 
> misa_ext_info_arr[] array will hold name and description for each MISA
> extension that misa_ext_cfgs[] is declaring. We'll then use this new
> array in KVM code to avoid duplicating strings. Two getters were added
> to allow KVM to retrieve the 'name' and 'description' for each MISA
> property.
> 
> There's nothing holding us back from doing the same with multi-letter
> extensions. For now doing just with MISA extensions is enough.
> 
> It is worth documenting that even using the __bultin_ctz() directive to
> populate the misa_ext_info_arr[] we are forced to assign 'name' and
> 'description' during runtime in riscv_cpu_add_misa_properties(). The
> reason is that some Gitlab runners ('clang-user' and 'tsan-build') will
> throw errors like this if we fetch 'name' and 'description' from the
> array in the MISA_CFG() macro:
> 
> ../target/riscv/cpu.c:1624:5: error: initializer element is not a
>                               compile-time constant
>     MISA_CFG(RVA, true),
>     ^~~~~~~~~~~~~~~~~~~
> ../target/riscv/cpu.c:1619:53: note: expanded from macro 'MISA_CFG'
>     {.name = misa_ext_info_arr[MISA_INFO_IDX(_bit)].name, \
>              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
> 
> gcc and others compilers/builders were fine with that change. We can't
> ignore failures in the Gitlab pipeline though, so code was changed to
> make every runner happy.
> 
> As a side effect, misa_ext_cfg[] is no longer a 'const' array because
> it must be set during runtime.
> 
> Suggested-by: Andrew Jones <ajones@ventanamicro.com>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  target/riscv/cpu.c | 110 +++++++++++++++++++++++++++++++++------------
>  target/riscv/cpu.h |   7 ++-
>  2 files changed, 88 insertions(+), 29 deletions(-)
> 
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 58439a05d1..c1693d5e9c 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -1558,33 +1558,83 @@ static void cpu_get_misa_ext_cfg(Object *obj, Visitor *v, const char *name,
>      visit_type_bool(v, name, &value, errp);
>  }
>  
> -static const RISCVCPUMisaExtConfig misa_ext_cfgs[] = {
> -    {.name = "a", .description = "Atomic instructions",
> -     .misa_bit = RVA, .enabled = true},
> -    {.name = "c", .description = "Compressed instructions",
> -     .misa_bit = RVC, .enabled = true},
> -    {.name = "d", .description = "Double-precision float point",
> -     .misa_bit = RVD, .enabled = true},
> -    {.name = "f", .description = "Single-precision float point",
> -     .misa_bit = RVF, .enabled = true},
> -    {.name = "i", .description = "Base integer instruction set",
> -     .misa_bit = RVI, .enabled = true},
> -    {.name = "e", .description = "Base integer instruction set (embedded)",
> -     .misa_bit = RVE, .enabled = false},
> -    {.name = "m", .description = "Integer multiplication and division",
> -     .misa_bit = RVM, .enabled = true},
> -    {.name = "s", .description = "Supervisor-level instructions",
> -     .misa_bit = RVS, .enabled = true},
> -    {.name = "u", .description = "User-level instructions",
> -     .misa_bit = RVU, .enabled = true},
> -    {.name = "h", .description = "Hypervisor",
> -     .misa_bit = RVH, .enabled = true},
> -    {.name = "x-j", .description = "Dynamic translated languages",
> -     .misa_bit = RVJ, .enabled = false},
> -    {.name = "v", .description = "Vector operations",
> -     .misa_bit = RVV, .enabled = false},
> -    {.name = "g", .description = "General purpose (IMAFD_Zicsr_Zifencei)",
> -     .misa_bit = RVG, .enabled = false},
> +typedef struct misa_ext_info {
> +    const char *name;
> +    const char *description;
> +} MISAExtInfo;
> +
> +#define MISA_INFO_IDX(_bit) \
> +    __builtin_ctz(_bit)
> +
> +#define MISA_EXT_INFO(_bit, _propname, _descr) \
> +    [MISA_INFO_IDX(_bit)] = {.name = _propname, .description = _descr}
> +
> +static const MISAExtInfo misa_ext_info_arr[] = {
> +    MISA_EXT_INFO(RVA, "a", "Atomic instructions"),
> +    MISA_EXT_INFO(RVC, "c", "Compressed instructions"),
> +    MISA_EXT_INFO(RVD, "d", "Double-precision float point"),
> +    MISA_EXT_INFO(RVF, "f", "Single-precision float point"),
> +    MISA_EXT_INFO(RVI, "i", "Base integer instruction set"),
> +    MISA_EXT_INFO(RVE, "e", "Base integer instruction set (embedded)"),
> +    MISA_EXT_INFO(RVM, "m", "Integer multiplication and division"),
> +    MISA_EXT_INFO(RVS, "s", "Supervisor-level instructions"),
> +    MISA_EXT_INFO(RVU, "u", "User-level instructions"),
> +    MISA_EXT_INFO(RVH, "h", "Hypervisor"),
> +    MISA_EXT_INFO(RVJ, "x-j", "Dynamic translated languages"),
> +    MISA_EXT_INFO(RVV, "v", "Vector operations"),
> +    MISA_EXT_INFO(RVG, "g", "General purpose (IMAFD_Zicsr_Zifencei)"),
> +};
> +
> +static int riscv_validate_misa_info_idx(uint32_t bit)
> +{
> +    int idx;
> +
> +    /*
> +     * Our lowest valid input (RVA) is 1 and
> +     * __builtin_ctz() is UB with zero.
> +     */
> +    g_assert(bit != 0);
> +    idx = MISA_INFO_IDX(bit);
> +
> +    g_assert(idx < ARRAY_SIZE(misa_ext_info_arr));
> +    return idx;
> +}
> +
> +const char *riscv_get_misa_ext_name(uint32_t bit)
> +{
> +    int idx = riscv_validate_misa_info_idx(bit);
> +    const char *val = misa_ext_info_arr[idx].name;
> +
> +    g_assert(val != NULL);
> +    return val;
> +}
> +
> +const char *riscv_get_misa_ext_description(uint32_t bit)
> +{
> +    int idx = riscv_validate_misa_info_idx(bit);
> +    const char *val = misa_ext_info_arr[idx].description;
> +
> +    g_assert(val != NULL);
> +    return val;
> +}
> +
> +#define MISA_CFG(_bit, _enabled) \
> +    {.misa_bit = _bit, .enabled = _enabled}
> +
> +static RISCVCPUMisaExtConfig misa_ext_cfgs[] = {
> +    MISA_CFG(RVA, true),
> +    MISA_CFG(RVC, true),
> +    MISA_CFG(RVD, true),
> +    MISA_CFG(RVF, true),
> +    MISA_CFG(RVI, true),
> +    MISA_CFG(RVE, false),
> +    MISA_CFG(RVM, true),
> +    MISA_CFG(RVS, true),
> +    MISA_CFG(RVU, true),
> +    MISA_CFG(RVH, true),
> +    MISA_CFG(RVJ, false),
> +    MISA_CFG(RVV, false),
> +    MISA_CFG(RVG, false),
>  };
>  
>  static void riscv_cpu_add_misa_properties(Object *cpu_obj)
> @@ -1592,7 +1642,11 @@ static void riscv_cpu_add_misa_properties(Object *cpu_obj)
>      int i;
>  
>      for (i = 0; i < ARRAY_SIZE(misa_ext_cfgs); i++) {
> -        const RISCVCPUMisaExtConfig *misa_cfg = &misa_ext_cfgs[i];
> +        RISCVCPUMisaExtConfig *misa_cfg = &misa_ext_cfgs[i];
> +        int bit = misa_cfg->misa_bit;
> +
> +        misa_cfg->name = riscv_get_misa_ext_name(bit);
> +        misa_cfg->description = riscv_get_misa_ext_description(bit);
>  
>          object_property_add(cpu_obj, misa_cfg->name, "bool",
>                              cpu_get_misa_ext_cfg,
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index cc20ee25a7..9830ec5f75 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -41,7 +41,10 @@
>  
>  #define RV(x) ((target_ulong)1 << (x - 'A'))
>  
> -/* Consider updating misa_ext_cfgs[] when adding new MISA bits here */
> +/*
> + * Consider updating misa_ext_info_arr[] and misa_ext_cfgs[]
> + * when adding new MISA bits here.
> + */
>  #define RVI RV('I')
>  #define RVE RV('E') /* E and I are mutually exclusive */
>  #define RVM RV('M')
> @@ -56,6 +59,8 @@
>  #define RVJ RV('J')
>  #define RVG RV('G')
>  
> +const char *riscv_get_misa_ext_name(uint32_t bit);
> +const char *riscv_get_misa_ext_description(uint32_t bit);
>  
>  /* Privileged specification version */
>  enum {
> -- 
> 2.41.0
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew

Re: [PATCH v7 12/20] target/riscv: add KVM specific MISA properties

[Andrew Jones]

On Fri, Jun 30, 2023 at 07:08:03AM -0300, Daniel Henrique Barboza wrote:
> Using all TCG user properties in KVM is tricky. First because KVM
> supports only a small subset of what TCG provides, so most of the
> cpu->cfg flags do nothing for KVM.
> 
> Second, and more important, we don't have a way of telling if any given
> value is an user input or not. For TCG this has a small impact since we
> just validating everything and error out if needed. But for KVM it would
> be good to know if a given value was set by the user or if it's a value
> already provided by KVM. Otherwise we don't know how to handle failed
> kvm_set_one_regs() when writing the configurations back.
> 
> These characteristics make it overly complicated to use the same user
> facing flags for both KVM and TCG. A simpler approach is to create KVM
> specific properties that have specialized logic, forking KVM and TCG use
> cases for those cases only. Fully separating KVM/TCG properties is
> unneeded at this point - in fact we want the user experience to be as
> equal as possible, regardless of the acceleration chosen.
> 
> We'll start this fork with the MISA properties, adding the MISA bits
> that the KVM driver currently supports. A new KVMCPUConfig type is
> introduced. It'll hold general information about an extension. For MISA
> extensions we're going to use the newly created getters of
> misa_ext_infos[] to populate their name and description. 'offset' holds
> the MISA bit (RVA, RVC, ...). We're calling it 'offset' instead of
> 'misa_bit' because this same KVMCPUConfig struct will be used to
> multi-letter extensions later on.
> 
> This new type also holds a 'user_set' flag. This flag will be set when
> the user set an option that's different than what is already configured
> in the host, requiring KVM intervention to write the regs back during
> kvm_arch_init_vcpu(). Similar mechanics will be implemented for
> multi-letter extensions as well.
> 
> There is no need to duplicate more code than necessary, so we're going
> to use the existing kvm_riscv_init_user_properties() to add the KVM
> specific properties. Any code that is adding a TCG user prop is then
> changed slightly to verify first if there's a KVM prop with the same
> name already added.
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  target/riscv/cpu.c |  5 +++
>  target/riscv/kvm.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 83 insertions(+)
> 
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index c1693d5e9c..a9df61c9b4 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -1648,6 +1648,11 @@ static void riscv_cpu_add_misa_properties(Object *cpu_obj)
>          misa_cfg->name = riscv_get_misa_ext_name(bit);
>          misa_cfg->description = riscv_get_misa_ext_description(bit);
>  
> +        /* Check if KVM already created the property */
> +        if (object_property_find(cpu_obj, misa_cfg->name)) {
> +            continue;
> +        }
> +
>          object_property_add(cpu_obj, misa_cfg->name, "bool",
>                              cpu_get_misa_ext_cfg,
>                              cpu_set_misa_ext_cfg,
> diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
> index 4d0808cb9a..c55d0ec7ab 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -22,8 +22,10 @@
>  #include <linux/kvm.h>
>  
>  #include "qemu/timer.h"
> +#include "qapi/error.h"
>  #include "qemu/error-report.h"
>  #include "qemu/main-loop.h"
> +#include "qapi/visitor.h"
>  #include "sysemu/sysemu.h"
>  #include "sysemu/kvm.h"
>  #include "sysemu/kvm_int.h"
> @@ -105,6 +107,81 @@ static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
>          } \
>      } while (0)
>  
> +typedef struct KVMCPUConfig {
> +    const char *name;
> +    const char *description;
> +    target_ulong offset;
> +    int kvm_reg_id;
> +    bool user_set;
> +} KVMCPUConfig;
> +
> +#define KVM_MISA_CFG(_bit, _reg_id) \
> +    {.offset = _bit, .kvm_reg_id = _reg_id}
> +
> +/* KVM ISA extensions */
> +static KVMCPUConfig kvm_misa_ext_cfgs[] = {
> +    KVM_MISA_CFG(RVA, KVM_RISCV_ISA_EXT_A),
> +    KVM_MISA_CFG(RVC, KVM_RISCV_ISA_EXT_C),
> +    KVM_MISA_CFG(RVD, KVM_RISCV_ISA_EXT_D),
> +    KVM_MISA_CFG(RVF, KVM_RISCV_ISA_EXT_F),
> +    KVM_MISA_CFG(RVH, KVM_RISCV_ISA_EXT_H),
> +    KVM_MISA_CFG(RVI, KVM_RISCV_ISA_EXT_I),
> +    KVM_MISA_CFG(RVM, KVM_RISCV_ISA_EXT_M),
> +};
> +
> +static void kvm_cpu_set_misa_ext_cfg(Object *obj, Visitor *v,
> +                                     const char *name,
> +                                     void *opaque, Error **errp)
> +{
> +    KVMCPUConfig *misa_ext_cfg = opaque;
> +    target_ulong misa_bit = misa_ext_cfg->offset;
> +    RISCVCPU *cpu = RISCV_CPU(obj);
> +    CPURISCVState *env = &cpu->env;
> +    bool value, host_bit;
> +
> +    if (!visit_type_bool(v, name, &value, errp)) {
> +        return;
> +    }
> +
> +    host_bit = env->misa_ext_mask & misa_bit;
> +
> +    if (value == host_bit) {
> +        return;
> +    }
> +
> +    if (!value) {
> +        misa_ext_cfg->user_set = true;
> +        return;
> +    }
> +
> +    /*
> +     * Forbid users to enable extensions that aren't
> +     * available in the hart.
> +     */
> +    error_setg(errp, "Enabling MISA bit '%s' is not allowed: it's not "
> +               "enabled in the host", misa_ext_cfg->name);
> +}
> +
> +static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
> +{
> +    int i;
> +
> +    for (i = 0; i < ARRAY_SIZE(kvm_misa_ext_cfgs); i++) {
> +        KVMCPUConfig *misa_cfg = &kvm_misa_ext_cfgs[i];
> +        int bit = misa_cfg->offset;
> +
> +        misa_cfg->name = riscv_get_misa_ext_name(bit);
> +        misa_cfg->description = riscv_get_misa_ext_description(bit);
> +
> +        object_property_add(cpu_obj, misa_cfg->name, "bool",
> +                            NULL,
> +                            kvm_cpu_set_misa_ext_cfg,
> +                            NULL, misa_cfg);
> +        object_property_set_description(cpu_obj, misa_cfg->name,
> +                                        misa_cfg->description);
> +    }
> +}
> +
>  static int kvm_riscv_get_regs_core(CPUState *cs)
>  {
>      int ret = 0;
> @@ -427,6 +504,7 @@ void kvm_riscv_init_user_properties(Object *cpu_obj)
>          return;
>      }
>  
> +    kvm_riscv_add_cpu_user_properties(cpu_obj);
>      kvm_riscv_init_machine_ids(cpu, &kvmcpu);
>      kvm_riscv_init_misa_ext_mask(cpu, &kvmcpu);
>  
> -- 
> 2.41.0
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew

Re: [PATCH v7 14/20] target/riscv/kvm.c: add multi-letter extension KVM properties

[Andrew Jones]

On Fri, Jun 30, 2023 at 07:08:05AM -0300, Daniel Henrique Barboza wrote:
> Let's add KVM user properties for the multi-letter extensions that KVM
> currently supports: zicbom, zicboz, zihintpause, zbb, ssaia, sstc,
> svinval and svpbmt.
> 
> As with MISA extensions, we're using the KVMCPUConfig type to hold
> information about the state of each extension. However, multi-letter
> extensions have more cases to cover than MISA extensions, so we're
> adding an extra 'supported' flag as well. This flag will reflect if a
> given extension is supported by KVM, i.e. KVM knows how to handle it.
> This is determined during KVM extension discovery in
> kvm_riscv_init_multiext_cfg(), where we test for EINVAL errors. Any
> other error different from EINVAL will cause an abort.
> 
> The use of the 'user_set' is similar to what we already do with MISA
> extensions: the flag set only if the user is changing the extension
> state.
> 
> The 'supported' flag will be used later on to make an exception for
> users that are disabling multi-letter extensions that are unknown to
> KVM.
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> ---
>  target/riscv/cpu.c |   8 +++
>  target/riscv/kvm.c | 119 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 127 insertions(+)
> 
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index a9df61c9b4..f348424170 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -1778,6 +1778,14 @@ static void riscv_cpu_add_user_properties(Object *obj)
>      riscv_cpu_add_misa_properties(obj);
>  
>      for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
> +#ifndef CONFIG_USER_ONLY
> +        if (kvm_enabled()) {
> +            /* Check if KVM created the property already */
> +            if (object_property_find(obj, prop->name)) {
> +                continue;
> +            }
> +        }
> +#endif
>          qdev_property_add_static(dev, prop);
>      }
>  
> diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
> index 7afd6024e6..6ef81a6825 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -113,6 +113,7 @@ typedef struct KVMCPUConfig {
>      target_ulong offset;
>      int kvm_reg_id;
>      bool user_set;
> +    bool supported;
>  } KVMCPUConfig;
>  
>  #define KVM_MISA_CFG(_bit, _reg_id) \
> @@ -197,6 +198,81 @@ static void kvm_riscv_update_cpu_misa_ext(RISCVCPU *cpu, CPUState *cs)
>      }
>  }
>  
> +#define CPUCFG(_prop) offsetof(struct RISCVCPUConfig, _prop)
> +
> +#define KVM_EXT_CFG(_name, _prop, _reg_id) \
> +    {.name = _name, .offset = CPUCFG(_prop), \
> +     .kvm_reg_id = _reg_id}
> +
> +static KVMCPUConfig kvm_multi_ext_cfgs[] = {
> +    KVM_EXT_CFG("zicbom", ext_icbom, KVM_RISCV_ISA_EXT_ZICBOM),
> +    KVM_EXT_CFG("zicboz", ext_icboz, KVM_RISCV_ISA_EXT_ZICBOZ),
> +    KVM_EXT_CFG("zihintpause", ext_zihintpause, KVM_RISCV_ISA_EXT_ZIHINTPAUSE),
> +    KVM_EXT_CFG("zbb", ext_zbb, KVM_RISCV_ISA_EXT_ZBB),
> +    KVM_EXT_CFG("ssaia", ext_ssaia, KVM_RISCV_ISA_EXT_SSAIA),
> +    KVM_EXT_CFG("sstc", ext_sstc, KVM_RISCV_ISA_EXT_SSTC),
> +    KVM_EXT_CFG("svinval", ext_svinval, KVM_RISCV_ISA_EXT_SVINVAL),
> +    KVM_EXT_CFG("svpbmt", ext_svpbmt, KVM_RISCV_ISA_EXT_SVPBMT),
> +};
> +
> +static void kvm_cpu_cfg_set(RISCVCPU *cpu, KVMCPUConfig *multi_ext,
> +                            uint32_t val)
> +{
> +    int cpu_cfg_offset = multi_ext->offset;
> +    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
> +
> +    *ext_enabled = val;
> +}
> +
> +static uint32_t kvm_cpu_cfg_get(RISCVCPU *cpu,
> +                                KVMCPUConfig *multi_ext)
> +{
> +    int cpu_cfg_offset = multi_ext->offset;
> +    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
> +
> +    return *ext_enabled;
> +}
> +
> +static void kvm_cpu_set_multi_ext_cfg(Object *obj, Visitor *v,
> +                                      const char *name,
> +                                      void *opaque, Error **errp)
> +{
> +    KVMCPUConfig *multi_ext_cfg = opaque;
> +    RISCVCPU *cpu = RISCV_CPU(obj);
> +    bool value, host_val;
> +
> +    if (!visit_type_bool(v, name, &value, errp)) {
> +        return;
> +    }
> +
> +    host_val = kvm_cpu_cfg_get(cpu, multi_ext_cfg);
> +
> +    /*
> +     * Ignore if the user is setting the same value
> +     * as the host.
> +     */
> +    if (value == host_val) {
> +        return;
> +    }
> +
> +    if (!multi_ext_cfg->supported) {
> +        /*
> +         * Error out if the user is trying to enable an
> +         * extension that KVM doesn't support. Ignore
> +         * option otherwise.
> +         */
> +        if (value) {
> +            error_setg(errp, "KVM does not support disabling extension %s",
> +                       multi_ext_cfg->name);
> +        }
> +
> +        return;
> +    }
> +
> +    multi_ext_cfg->user_set = true;
> +    kvm_cpu_cfg_set(cpu, multi_ext_cfg, value);
> +}
> +
>  static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
>  {
>      int i;
> @@ -215,6 +291,15 @@ static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
>          object_property_set_description(cpu_obj, misa_cfg->name,
>                                          misa_cfg->description);
>      }
> +
> +    for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) {
> +        KVMCPUConfig *multi_cfg = &kvm_multi_ext_cfgs[i];
> +
> +        object_property_add(cpu_obj, multi_cfg->name, "bool",
> +                            NULL,
> +                            kvm_cpu_set_multi_ext_cfg,
> +                            NULL, multi_cfg);
> +    }
>  }
>  
>  static int kvm_riscv_get_regs_core(CPUState *cs)
> @@ -530,6 +615,39 @@ static void kvm_riscv_init_misa_ext_mask(RISCVCPU *cpu,
>      env->misa_ext = env->misa_ext_mask;
>  }
>  
> +static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
> +{
> +    CPURISCVState *env = &cpu->env;
> +    uint64_t val;
> +    int i, ret;
> +
> +    for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) {
> +        KVMCPUConfig *multi_ext_cfg = &kvm_multi_ext_cfgs[i];
> +        struct kvm_one_reg reg;
> +
> +        reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_ISA_EXT,
> +                                  multi_ext_cfg->kvm_reg_id);
> +        reg.addr = (uint64_t)&val;
> +        ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
> +        if (ret != 0) {

As discussed internally on Slack, since we can't use kvm_vcpu_ioctl() here
we need to properly check 'if (ret == -1)'

> +            if (ret == -EINVAL) {

and here 'if (errno == EINVAL)'. But, also as discussed internally, based
on our upcoming plans to use ENOENT for missing registers, we should
change this check to be for ENOENT now. While that may seem premature, I
think it's OK, because until a KVM which returns ENOENT for missing
registers exists and is used, QEMU command lines which disable unknown
registers will be rejected. But, that will also happen even after a KVM
that returns ENOENT exits if an older KVM is used. In both cases that's
fine, as rejecting is the more conservative behavior for an error.
Finally, if the yet-to-be-posted KVM ENOENT patch never gets merged, then
we may be stuck rejecting forever anyway, since EINVAL is quite generic
and probably isn't safe to use for this purpose.

Thanks,
drew


> +                /* Silently default to 'false' if KVM does not support it. */
> +                multi_ext_cfg->supported = false;
> +                val = false;
> +            } else {
> +                error_report("Unable to read ISA_EXT KVM register %s, "
> +                             "error %d", multi_ext_cfg->name, ret);
> +                kvm_riscv_destroy_scratch_vcpu(kvmcpu);
> +                exit(EXIT_FAILURE);
> +            }
> +        } else {
> +            multi_ext_cfg->supported = true;
> +        }
> +
> +        kvm_cpu_cfg_set(cpu, multi_ext_cfg, val);
> +    }
> +}
> +
>  void kvm_riscv_init_user_properties(Object *cpu_obj)
>  {
>      RISCVCPU *cpu = RISCV_CPU(cpu_obj);
> @@ -542,6 +660,7 @@ void kvm_riscv_init_user_properties(Object *cpu_obj)
>      kvm_riscv_add_cpu_user_properties(cpu_obj);
>      kvm_riscv_init_machine_ids(cpu, &kvmcpu);
>      kvm_riscv_init_misa_ext_mask(cpu, &kvmcpu);
> +    kvm_riscv_init_multiext_cfg(cpu, &kvmcpu);
>  
>      kvm_riscv_destroy_scratch_vcpu(&kvmcpu);
>  }
> -- 
> 2.41.0
> 

Re: [PATCH v7 14/20] target/riscv/kvm.c: add multi-letter extension KVM properties

[Daniel Henrique Barboza]

On 7/5/23 10:41, Andrew Jones wrote:
> On Fri, Jun 30, 2023 at 07:08:05AM -0300, Daniel Henrique Barboza wrote:
>> Let's add KVM user properties for the multi-letter extensions that KVM
>> currently supports: zicbom, zicboz, zihintpause, zbb, ssaia, sstc,
>> svinval and svpbmt.
>>
>> As with MISA extensions, we're using the KVMCPUConfig type to hold
>> information about the state of each extension. However, multi-letter
>> extensions have more cases to cover than MISA extensions, so we're
>> adding an extra 'supported' flag as well. This flag will reflect if a
>> given extension is supported by KVM, i.e. KVM knows how to handle it.
>> This is determined during KVM extension discovery in
>> kvm_riscv_init_multiext_cfg(), where we test for EINVAL errors. Any
>> other error different from EINVAL will cause an abort.
>>
>> The use of the 'user_set' is similar to what we already do with MISA
>> extensions: the flag set only if the user is changing the extension
>> state.
>>
>> The 'supported' flag will be used later on to make an exception for
>> users that are disabling multi-letter extensions that are unknown to
>> KVM.
>>
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
>> ---
>>   target/riscv/cpu.c |   8 +++
>>   target/riscv/kvm.c | 119 +++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 127 insertions(+)
>>
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> index a9df61c9b4..f348424170 100644
>> --- a/target/riscv/cpu.c
>> +++ b/target/riscv/cpu.c
>> @@ -1778,6 +1778,14 @@ static void riscv_cpu_add_user_properties(Object *obj)
>>       riscv_cpu_add_misa_properties(obj);
>>   
>>       for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
>> +#ifndef CONFIG_USER_ONLY
>> +        if (kvm_enabled()) {
>> +            /* Check if KVM created the property already */
>> +            if (object_property_find(obj, prop->name)) {
>> +                continue;
>> +            }
>> +        }
>> +#endif
>>           qdev_property_add_static(dev, prop);
>>       }
>>   
>> diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
>> index 7afd6024e6..6ef81a6825 100644
>> --- a/target/riscv/kvm.c
>> +++ b/target/riscv/kvm.c
>> @@ -113,6 +113,7 @@ typedef struct KVMCPUConfig {
>>       target_ulong offset;
>>       int kvm_reg_id;
>>       bool user_set;
>> +    bool supported;
>>   } KVMCPUConfig;
>>   
>>   #define KVM_MISA_CFG(_bit, _reg_id) \
>> @@ -197,6 +198,81 @@ static void kvm_riscv_update_cpu_misa_ext(RISCVCPU *cpu, CPUState *cs)
>>       }
>>   }
>>   
>> +#define CPUCFG(_prop) offsetof(struct RISCVCPUConfig, _prop)
>> +
>> +#define KVM_EXT_CFG(_name, _prop, _reg_id) \
>> +    {.name = _name, .offset = CPUCFG(_prop), \
>> +     .kvm_reg_id = _reg_id}
>> +
>> +static KVMCPUConfig kvm_multi_ext_cfgs[] = {
>> +    KVM_EXT_CFG("zicbom", ext_icbom, KVM_RISCV_ISA_EXT_ZICBOM),
>> +    KVM_EXT_CFG("zicboz", ext_icboz, KVM_RISCV_ISA_EXT_ZICBOZ),
>> +    KVM_EXT_CFG("zihintpause", ext_zihintpause, KVM_RISCV_ISA_EXT_ZIHINTPAUSE),
>> +    KVM_EXT_CFG("zbb", ext_zbb, KVM_RISCV_ISA_EXT_ZBB),
>> +    KVM_EXT_CFG("ssaia", ext_ssaia, KVM_RISCV_ISA_EXT_SSAIA),
>> +    KVM_EXT_CFG("sstc", ext_sstc, KVM_RISCV_ISA_EXT_SSTC),
>> +    KVM_EXT_CFG("svinval", ext_svinval, KVM_RISCV_ISA_EXT_SVINVAL),
>> +    KVM_EXT_CFG("svpbmt", ext_svpbmt, KVM_RISCV_ISA_EXT_SVPBMT),
>> +};
>> +
>> +static void kvm_cpu_cfg_set(RISCVCPU *cpu, KVMCPUConfig *multi_ext,
>> +                            uint32_t val)
>> +{
>> +    int cpu_cfg_offset = multi_ext->offset;
>> +    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
>> +
>> +    *ext_enabled = val;
>> +}
>> +
>> +static uint32_t kvm_cpu_cfg_get(RISCVCPU *cpu,
>> +                                KVMCPUConfig *multi_ext)
>> +{
>> +    int cpu_cfg_offset = multi_ext->offset;
>> +    bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset;
>> +
>> +    return *ext_enabled;
>> +}
>> +
>> +static void kvm_cpu_set_multi_ext_cfg(Object *obj, Visitor *v,
>> +                                      const char *name,
>> +                                      void *opaque, Error **errp)
>> +{
>> +    KVMCPUConfig *multi_ext_cfg = opaque;
>> +    RISCVCPU *cpu = RISCV_CPU(obj);
>> +    bool value, host_val;
>> +
>> +    if (!visit_type_bool(v, name, &value, errp)) {
>> +        return;
>> +    }
>> +
>> +    host_val = kvm_cpu_cfg_get(cpu, multi_ext_cfg);
>> +
>> +    /*
>> +     * Ignore if the user is setting the same value
>> +     * as the host.
>> +     */
>> +    if (value == host_val) {
>> +        return;
>> +    }
>> +
>> +    if (!multi_ext_cfg->supported) {
>> +        /*
>> +         * Error out if the user is trying to enable an
>> +         * extension that KVM doesn't support. Ignore
>> +         * option otherwise.
>> +         */
>> +        if (value) {
>> +            error_setg(errp, "KVM does not support disabling extension %s",
>> +                       multi_ext_cfg->name);
>> +        }
>> +
>> +        return;
>> +    }
>> +
>> +    multi_ext_cfg->user_set = true;
>> +    kvm_cpu_cfg_set(cpu, multi_ext_cfg, value);
>> +}
>> +
>>   static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
>>   {
>>       int i;
>> @@ -215,6 +291,15 @@ static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
>>           object_property_set_description(cpu_obj, misa_cfg->name,
>>                                           misa_cfg->description);
>>       }
>> +
>> +    for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) {
>> +        KVMCPUConfig *multi_cfg = &kvm_multi_ext_cfgs[i];
>> +
>> +        object_property_add(cpu_obj, multi_cfg->name, "bool",
>> +                            NULL,
>> +                            kvm_cpu_set_multi_ext_cfg,
>> +                            NULL, multi_cfg);
>> +    }
>>   }
>>   
>>   static int kvm_riscv_get_regs_core(CPUState *cs)
>> @@ -530,6 +615,39 @@ static void kvm_riscv_init_misa_ext_mask(RISCVCPU *cpu,
>>       env->misa_ext = env->misa_ext_mask;
>>   }
>>   
>> +static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
>> +{
>> +    CPURISCVState *env = &cpu->env;
>> +    uint64_t val;
>> +    int i, ret;
>> +
>> +    for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) {
>> +        KVMCPUConfig *multi_ext_cfg = &kvm_multi_ext_cfgs[i];
>> +        struct kvm_one_reg reg;
>> +
>> +        reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_ISA_EXT,
>> +                                  multi_ext_cfg->kvm_reg_id);
>> +        reg.addr = (uint64_t)&val;
>> +        ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
>> +        if (ret != 0) {
> 
> As discussed internally on Slack, since we can't use kvm_vcpu_ioctl() here
> we need to properly check 'if (ret == -1)'
> 
>> +            if (ret == -EINVAL) {
> 
> and here 'if (errno == EINVAL)'. But, also as discussed internally, based
> on our upcoming plans to use ENOENT for missing registers, we should
> change this check to be for ENOENT now. While that may seem premature, I
> think it's OK, because until a KVM which returns ENOENT for missing
> registers exists and is used, QEMU command lines which disable unknown
> registers will be rejected. But, that will also happen even after a KVM
> that returns ENOENT exits if an older KVM is used. In both cases that's
> fine, as rejecting is the more conservative behavior for an error.
> Finally, if the yet-to-be-posted KVM ENOENT patch never gets merged, then
> we may be stuck rejecting forever anyway, since EINVAL is quite generic
> and probably isn't safe to use for this purpose.


I agree. I'll re-send v8 right away with the 'errno' fix and changing the
check to use ENOENT instead of EINVAL.

Even if we don't manage to change KVM to use ENOENT in these situations (reg
does not exist/extension does not exist), the assumption made here does not
hold water anyway because EINVAL is being thrown for all sort of errors, so
might as well error out.

So changing for ENOENT is good if we manage to change KVM, and if we fail to
change it it we'll end up erroring out on all errors, which is saner than
having to take a guess on what EINVAL means.



Thanks,

Daniel


> 
> Thanks,
> drew
> 
> 
>> +                /* Silently default to 'false' if KVM does not support it. */
>> +                multi_ext_cfg->supported = false;
>> +                val = false;
>> +            } else {
>> +                error_report("Unable to read ISA_EXT KVM register %s, "
>> +                             "error %d", multi_ext_cfg->name, ret);
>> +                kvm_riscv_destroy_scratch_vcpu(kvmcpu);
>> +                exit(EXIT_FAILURE);
>> +            }
>> +        } else {
>> +            multi_ext_cfg->supported = true;
>> +        }
>> +
>> +        kvm_cpu_cfg_set(cpu, multi_ext_cfg, val);
>> +    }
>> +}
>> +
>>   void kvm_riscv_init_user_properties(Object *cpu_obj)
>>   {
>>       RISCVCPU *cpu = RISCV_CPU(cpu_obj);
>> @@ -542,6 +660,7 @@ void kvm_riscv_init_user_properties(Object *cpu_obj)
>>       kvm_riscv_add_cpu_user_properties(cpu_obj);
>>       kvm_riscv_init_machine_ids(cpu, &kvmcpu);
>>       kvm_riscv_init_misa_ext_mask(cpu, &kvmcpu);
>> +    kvm_riscv_init_multiext_cfg(cpu, &kvmcpu);
>>   
>>       kvm_riscv_destroy_scratch_vcpu(&kvmcpu);
>>   }
>> -- 
>> 2.41.0
>>