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hypervisor: vmm: passing nested argument from VMM to hypervisor

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This patch connects the VMM and hypervisor to fully enable nested
support for MSHV.

Signed-off-by: Muminul Islam <muislam@microsoft.com>
This commit is contained in:
Muminul Islam 2025-10-07 16:25:48 -07:00 • committed by Rob Bradford
parent f10d0bb33d
commit d8360ddc8e
3 changed files with 40 additions and 4 deletions
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1
hypervisor/src/lib.rs
View file

@ -170,6 +170,7 @@ pub struct HypervisorVmConfig {
pub sev_snp_enabled: bool,
#[cfg(feature = "sev_snp")]
pub mem_size: u64,
pub nested: bool,
}
#[derive(Copy, Clone)]

42
hypervisor/src/mshv/mod.rs
View file

@ -14,7 +14,10 @@ use log::{debug, warn};
use mshv_bindings::*;
#[cfg(target_arch = "x86_64")]
use mshv_ioctls::InterruptRequest;
use mshv_ioctls::{Mshv, NoDatamatch, VcpuFd, VmFd, VmType, set_registers_64};
use mshv_ioctls::{
Mshv, NoDatamatch, VcpuFd, VmFd, VmType, make_default_partition_create_arg,
make_default_synthetic_features_mask, set_registers_64,
};
use vfio_ioctls::VfioDeviceFd;
use vm::DataMatch;
#[cfg(feature = "sev_snp")]
@ -292,10 +295,37 @@ impl hypervisor::Hypervisor for MshvHypervisor {
VmType::Normal
};
}
let mut create_args = make_default_partition_create_arg(mshv_vm_type);
let mut disable_proc_features = hv_partition_processor_features::default();
// SAFETY: Accessing a union element from bindgen generated bindings.
unsafe {
for i in 0..create_args.pt_num_cpu_fbanks {
disable_proc_features.as_uint64[i as usize] = create_args.pt_cpu_fbanks[i as usize];
}
#[cfg(target_arch = "x86_64")]
{
// Modify create_args based on user configuration
// For now we only handle nested virtualization, but more features can be added here
if _config.nested {
create_args.pt_flags |= 1 << MSHV_PT_BIT_NESTED_VIRTUALIZATION;
disable_proc_features
.__bindgen_anon_1
.set_nested_virt_support(0u64);
} else {
disable_proc_features
.__bindgen_anon_1
.set_nested_virt_support(1u64);
}
}
// Modified feature bit fields are written back to create_args
for i in 0..create_args.pt_num_cpu_fbanks {
create_args.pt_cpu_fbanks[i as usize] = disable_proc_features.as_uint64[i as usize];
}
}
let synthetic_features_mask = make_default_synthetic_features_mask();
let fd: VmFd;
loop {
match self.mshv.create_vm_with_type(mshv_vm_type) {
match self.mshv.create_vm_with_args(&create_args) {
Ok(res) => fd = res,
Err(e) => {
if e.errno() == libc::EINTR {
@ -309,7 +339,11 @@ impl hypervisor::Hypervisor for MshvHypervisor {
}
break;
}
fd.set_partition_property(
hv_partition_property_code_HV_PARTITION_PROPERTY_SYNTHETIC_PROC_FEATURES,
synthetic_features_mask,
)
.map_err(|e| hypervisor::HypervisorError::SetPartitionProperty(e.into()))?;
let vm_fd = Arc::new(fd);
#[cfg(target_arch = "x86_64")]

1
vmm/src/lib.rs
View file

@ -220,6 +220,7 @@ impl From<&VmConfig> for hypervisor::HypervisorVmConfig {
sev_snp_enabled: _value.is_sev_snp_enabled(),
#[cfg(feature = "sev_snp")]
mem_size: _value.memory.total_size(),
nested: _value.cpus.nested,
}
}
}