hypervisor: mshv: hook up TranslateGVA hypercall

At this stage this is the bare minimum needed to make Windows server
2019 work on MSHV.

Signed-off-by: Wei Liu <liuwe@microsoft.com>

Cargo.lock

@@ -624,7 +624,7 @@ dependencies = [
 [[package]]
 name = "mshv-bindings"
 version = "0.1.0"
-source = "git+https://github.com/cloud-hypervisor/mshv?branch=master#547b86e74096a51ca7b9ec6737f5ec1baf5bbdea"
+source = "git+https://github.com/cloud-hypervisor/mshv?branch=master#e1e078b51fb049b38e5db32cacd44569c0ea5a1f"
 dependencies = [
  "libc",
  "serde",
@@ -636,7 +636,7 @@ dependencies = [
 [[package]]
 name = "mshv-ioctls"
 version = "0.1.0"
-source = "git+https://github.com/cloud-hypervisor/mshv?branch=master#547b86e74096a51ca7b9ec6737f5ec1baf5bbdea"
+source = "git+https://github.com/cloud-hypervisor/mshv?branch=master#e1e078b51fb049b38e5db32cacd44569c0ea5a1f"
 dependencies = [
  "libc",
  "mshv-bindings",

hypervisor/src/arch/emulator/mod.rs

@@ -47,8 +47,8 @@ pub enum PlatformError {
     #[error("Set CPU state failure: {0}")]
     SetCpuStateFailure(#[source] anyhow::Error),
 
-    #[error("Unmapped virtual address: {0}")]
-    UnmappedGVA(#[source] anyhow::Error),
+    #[error("Translate virtual address: {0}")]
+    TranslateGVA(#[source] anyhow::Error),
 
     #[error("Unsupported CPU Mode: {0}")]
     UnsupportedCpuMode(#[source] anyhow::Error),

hypervisor/src/cpu.rs

@@ -23,6 +23,8 @@ use crate::CpuState;
 use crate::MpState;
 #[cfg(target_arch = "x86_64")]
 use crate::Xsave;
+#[cfg(feature = "mshv")]
+use mshv_bindings::*;
 use thiserror::Error;
 
 #[derive(Error, Debug)]
@@ -198,6 +200,11 @@ pub enum HypervisorCpuError {
     ///
     #[error("Failed to set system register: {0}")]
     SetSysRegister(#[source] anyhow::Error),
+    ///
+    /// GVA translation error
+    ///
+    #[error("Failed to translate GVA: {0}")]
+    TranslateGVA(#[source] anyhow::Error),
 }
 
 #[derive(Debug)]
@@ -398,4 +405,9 @@ pub trait Vcpu: Send + Sync {
     /// Triggers the running of the current virtual CPU returning an exit reason.
     ///
     fn run(&self) -> std::result::Result<VmExit, HypervisorCpuError>;
+    #[cfg(all(feature = "mshv", target_arch = "x86_64"))]
+    ///
+    /// Translate guest virtual address to guest physical address
+    ///
+    fn translate_gva(&self, gva: u64, flags: u64) -> Result<(u64, hv_translate_gva_result)>;
 }

hypervisor/src/mshv/mod.rs

@@ -528,6 +528,18 @@ impl cpu::Vcpu for MshvVcpu {
             xsave,
         })
     }
+    #[cfg(target_arch = "x86_64")]
+    ///
+    /// Translate guest virtual address to guest physical address
+    ///
+    fn translate_gva(&self, gva: u64, flags: u64) -> cpu::Result<(u64, hv_translate_gva_result)> {
+        let r = self
+            .fd
+            .translate_gva(gva, flags)
+            .map_err(|e| cpu::HypervisorCpuError::TranslateGVA(e.into()))?;
+
+        Ok(r)
+    }
 }
 
 struct MshvEmulatorContext<'a> {
@@ -537,14 +549,25 @@ struct MshvEmulatorContext<'a> {
 
 impl<'a> MshvEmulatorContext<'a> {
     // Do the actual gva -> gpa translation
+    #[allow(non_upper_case_globals)]
     fn translate(&self, gva: u64) -> Result<u64, PlatformError> {
         if self.map.0 == gva {
             return Ok(self.map.1);
         }
 
-        // TODO Check if we could fallback to e.g. an hypercall for doing
-        // the translation for us.
-        todo!()
+        // TODO: More fine-grained control for the flags
+        let flags = HV_TRANSLATE_GVA_VALIDATE_READ | HV_TRANSLATE_GVA_VALIDATE_WRITE;
+
+        let r = self
+            .vcpu
+            .translate_gva(gva, flags.into())
+            .map_err(|e| PlatformError::TranslateGVA(anyhow!(e)))?;
+
+        let result_code = unsafe { r.1.__bindgen_anon_1.result_code };
+        match result_code {
+            hv_translate_gva_result_code_HvTranslateGvaSuccess => Ok(r.0),
+            _ => Err(PlatformError::TranslateGVA(anyhow!(result_code))),
+        }
     }
 }