On 09/12/2022 09:56, David Woodhouse wrote:
From: Joao Martins <joao.m.mart...@oracle.com>
Handle the hypercall to set a per vcpu info, and also wire up the default
vcpu_info in the shared_info page for the first 32 vCPUs.
To avoid deadlock within KVM a vCPU thread must set its *own* vcpu_info
rather than it being set from the context in which the hypercall is
invoked.
Add the vcpu_info (and default) GPA to the vmstate_x86_cpu for migration,
and restore it in kvm_arch_put_registers() appropriately.
Signed-off-by: Joao Martins <joao.m.mart...@oracle.com>
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
---
target/i386/cpu.h | 2 ++
target/i386/kvm/kvm.c | 19 +++++++++++
target/i386/machine.c | 21 ++++++++++++
target/i386/trace-events | 1 +
target/i386/xen.c | 74 +++++++++++++++++++++++++++++++++++++---
target/i386/xen.h | 1 +
6 files changed, 113 insertions(+), 5 deletions(-)
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index c6c57baed5..109b2e5669 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1788,6 +1788,8 @@ typedef struct CPUArchState {
#endif
#if defined(CONFIG_KVM)
struct kvm_nested_state *nested_state;
+ uint64_t xen_vcpu_info_gpa;
+ uint64_t xen_vcpu_info_default_gpa;
#endif
#if defined(CONFIG_HVF)
HVFX86LazyFlags hvf_lflags;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index ebde6bc204..fa45e2f99a 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1811,6 +1811,9 @@ int kvm_arch_init_vcpu(CPUState *cs)
has_msr_hv_hypercall = true;
}
+ env->xen_vcpu_info_gpa = UINT64_MAX;
+ env->xen_vcpu_info_default_gpa = UINT64_MAX;
There was an INVALID_GPA definition for shared info. Looks like we could
use it here too.
+
xen_version = kvm_arch_xen_version(MACHINE(qdev_get_machine()));
if (xen_version) {
#ifdef CONFIG_XEN_EMU
@@ -4728,6 +4731,22 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
kvm_arch_set_tsc_khz(cpu);
}
+#ifdef CONFIG_XEN_EMU
+ if (level == KVM_PUT_FULL_STATE) {
+ uint64_t gpa = x86_cpu->env.xen_vcpu_info_gpa;
+ if (gpa == UINT64_MAX) {
+ gpa = x86_cpu->env.xen_vcpu_info_default_gpa;
+ }
+
+ if (gpa != UINT64_MAX) {
+ ret = kvm_xen_set_vcpu_attr(cpu, KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO,
gpa);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+ }
+#endif
+
ret = kvm_getput_regs(x86_cpu, 1);
if (ret < 0) {
return ret;
[snip]
@@ -195,19 +240,38 @@ static bool kvm_xen_hcall_hvm_op(struct kvm_xen_exit
*exit,
}
}
+static int vcpuop_register_vcpu_info(CPUState *cs, CPUState *target,
+ uint64_t arg)
+{
+ struct vcpu_register_vcpu_info rvi;
+ uint64_t gpa;
+
+ if (!target)
+ return -ENOENT;
+
+ if (kvm_copy_from_gva(cs, arg, &rvi, sizeof(rvi))) {
+ return -EFAULT;
+ }
+
+ gpa = ((rvi.mfn << TARGET_PAGE_BITS) + rvi.offset);
Some sanity checks wouldn't go a miss here...
rvi.offset should:
a) be < TARGET_PAGE_SIZE, and
b) ba aligned to vcpu_info_t size
Paul
+ async_run_on_cpu(target, do_set_vcpu_info_gpa, RUN_ON_CPU_HOST_ULONG(gpa));
+ return 0;
+}
+
