[PATCH 1/1] cpu_riscv64.c: add update() implementation
At this moment it is not possible to launch a 'riscv64' domain of type
'qemu' (i.e. TCG) and machine 'virt' in a x86 host:
$ sudo ./run tools/virsh start riscv-virt1
error: Failed to start domain 'riscv-virt1'
error: this function is not supported by the connection driver:
cannot update guest CPU for riscv64 architecture
A guest CPU definition will be added if absent by
qemuDomainSetDefaultCPU():
<cpu mode='custom' match='exact' check='none'>
<model fallback='forbid'>rv64</model>
</cpu>
This def will then be updated in qemuProcessUpdateGuestCPU(), which
calls virCPUUpdate(). The error above is being thrown by this function
because the current RISC-V driver does not have an 'update' API
implemented.
There is no particular reason to not support TCG RISC-V guests in x86 or
any other host arch, so let's add an 'update' API to the RISC-V driver.
The code was copied from virCPUarmUpdate() from the ARM driver since
it's a good enough implementation to get us started.
Signed-off-by: Daniel Henrique Barboza <dbarboza(a)ventanamicro.com>
---
src/cpu/cpu_riscv64.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/src/cpu/cpu_riscv64.c b/src/cpu/cpu_riscv64.c
index c44bdeb291..9796f8c967 100644
--- a/src/cpu/cpu_riscv64.c
+++ b/src/cpu/cpu_riscv64.c
@@ -46,6 +46,32 @@ virCPURiscv64ValidateFeatures(virCPUDef *cpu G_GNUC_UNUSED)
}
+static int
+virCPUriscvUpdate(virCPUDef *guest,
+ const virCPUDef *host,
+ bool relative)
+{
+ g_autoptr(virCPUDef) updated = virCPUDefCopyWithoutModel(guest);
+
+ if (!relative || guest->mode != VIR_CPU_MODE_HOST_MODEL)
+ return 0;
+
+ if (!host) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("unknown host CPU model"));
+ return -1;
+ }
+
+ updated->mode = VIR_CPU_MODE_CUSTOM;
+ virCPUDefCopyModel(updated, host, true);
+
+ virCPUDefStealModel(guest, updated, false);
+ guest->mode = VIR_CPU_MODE_CUSTOM;
+ guest->match = VIR_CPU_MATCH_EXACT;
+
+ return 0;
+}
+
struct cpuArchDriver cpuDriverRiscv64 = {
.name = "riscv64",
.arch = archs,
@@ -54,6 +80,6 @@ struct cpuArchDriver cpuDriverRiscv64 = {
.decode = NULL,
.encode = NULL,
.baseline = NULL,
- .update = NULL,
+ .update = virCPUriscvUpdate,
.validateFeatures = virCPURiscv64ValidateFeatures,
};
--
2.40.0