platform: move I/O port driver into platform abstraction

The `SVSMIOPort` and `NativeIOPort` objects are platform-specific, and
thus they should be implemented in the platform abstraction instead of
in common code.  Furthermore, the console serial port object is common
and need not be duplicated in every platform abstraction.

Signed-off-by: Jon Lange <[email protected]>

kernel/src/console.rs

@@ -4,8 +4,10 @@
 //
 // Author: Joerg Roedel <[email protected]>
 
+use crate::error::SvsmError;
+use crate::io::IOPort;
 use crate::locking::SpinLock;
-use crate::serial::{Terminal, DEFAULT_SERIAL_PORT};
+use crate::serial::{SerialPort, Terminal, DEFAULT_SERIAL_PORT};
 use crate::utils::immut_after_init::{ImmutAfterInitCell, ImmutAfterInitResult};
 use core::fmt;
 
@@ -27,14 +29,23 @@ static WRITER: SpinLock<Console> = SpinLock::new(Console {
     writer: &DEFAULT_SERIAL_PORT,
 });
 static CONSOLE_INITIALIZED: ImmutAfterInitCell<bool> = ImmutAfterInitCell::new(false);
+static CONSOLE_SERIAL: ImmutAfterInitCell<SerialPort<'_>> = ImmutAfterInitCell::uninit();
 
-pub fn init_console(writer: &'static dyn Terminal) -> ImmutAfterInitResult<()> {
+fn init_console(writer: &'static dyn Terminal) -> ImmutAfterInitResult<()> {
     WRITER.lock().writer = writer;
     CONSOLE_INITIALIZED.reinit(&true)?;
     log::info!("COCONUT Secure Virtual Machine Service Module");
     Ok(())
 }
 
+pub fn init_svsm_console(writer: &'static dyn IOPort, port: u16) -> Result<(), SvsmError> {
+    CONSOLE_SERIAL
+        .init(&SerialPort::new(writer, port))
+        .map_err(|_| SvsmError::Console)?;
+    (*CONSOLE_SERIAL).init();
+    init_console(&*CONSOLE_SERIAL).map_err(|_| SvsmError::Console)
+}
+
 #[doc(hidden)]
 pub fn _print(args: fmt::Arguments<'_>) {
     use core::fmt::Write;

kernel/src/lib.rs

@@ -34,7 +34,6 @@ pub mod requests;
 pub mod serial;
 pub mod sev;
 pub mod string;
-pub mod svsm_console;
 pub mod svsm_paging;
 pub mod syscall;
 pub mod task;

kernel/src/platform/native.rs

@@ -5,22 +5,16 @@
 // Author: Jon Lange <[email protected]>
 
 use crate::address::{PhysAddr, VirtAddr};
-use crate::console::init_console;
+use crate::console::init_svsm_console;
 use crate::cpu::cpuid::CpuidResult;
 use crate::cpu::msr::write_msr;
 use crate::cpu::percpu::PerCpu;
 use crate::error::SvsmError;
-use crate::io::IOPort;
+use crate::io::{IOPort, DEFAULT_IO_DRIVER};
 use crate::platform::{PageEncryptionMasks, PageStateChangeOp, SvsmPlatform};
-use crate::serial::SerialPort;
-use crate::svsm_console::NativeIOPort;
 use crate::types::PageSize;
-use crate::utils::immut_after_init::ImmutAfterInitCell;
 use crate::utils::MemoryRegion;
 
-static CONSOLE_IO: NativeIOPort = NativeIOPort::new();
-static CONSOLE_SERIAL: ImmutAfterInitCell<SerialPort<'_>> = ImmutAfterInitCell::uninit();
-
 const APIC_MSR_ICR: u32 = 0x830;
 
 #[derive(Clone, Copy, Debug)]
@@ -42,11 +36,7 @@ impl SvsmPlatform for NativePlatform {
     fn env_setup(&mut self, debug_serial_port: u16, _vtom: usize) -> Result<(), SvsmError> {
         // In the native platform, console output does not require the use of
         // any platform services, so it can be initialized immediately.
-        CONSOLE_SERIAL
-            .init(&SerialPort::new(&CONSOLE_IO, debug_serial_port))
-            .map_err(|_| SvsmError::Console)?;
-        (*CONSOLE_SERIAL).init();
-        init_console(&*CONSOLE_SERIAL).map_err(|_| SvsmError::Console)
+        init_svsm_console(&DEFAULT_IO_DRIVER, debug_serial_port)
     }
 
     fn env_setup_late(&mut self, _debug_serial_port: u16) -> Result<(), SvsmError> {
@@ -83,7 +73,7 @@ impl SvsmPlatform for NativePlatform {
     fn setup_guest_host_comm(&mut self, _cpu: &PerCpu, _is_bsp: bool) {}
 
     fn get_io_port(&self) -> &'static dyn IOPort {
-        &CONSOLE_IO
+        &DEFAULT_IO_DRIVER
     }
 
     fn page_state_change(

kernel/src/platform/snp.rs

@@ -5,29 +5,29 @@
 // Author: Jon Lange <[email protected]>
 
 use crate::address::{PhysAddr, VirtAddr};
-use crate::console::init_console;
+use crate::console::init_svsm_console;
 use crate::cpu::cpuid::{cpuid_table, CpuidResult};
 use crate::cpu::percpu::{current_ghcb, this_cpu, PerCpu};
 use crate::error::ApicError::Registration;
 use crate::error::SvsmError;
 use crate::io::IOPort;
 use crate::platform::{PageEncryptionMasks, PageStateChangeOp, SvsmPlatform};
-use crate::serial::SerialPort;
+use crate::sev::ghcb::GHCBIOSize;
 use crate::sev::hv_doorbell::current_hv_doorbell;
-use crate::sev::msr_protocol::{hypervisor_ghcb_features, verify_ghcb_version, GHCBHvFeatures};
+use crate::sev::msr_protocol::{
+    hypervisor_ghcb_features, request_termination_msr, verify_ghcb_version, GHCBHvFeatures,
+};
 use crate::sev::status::vtom_enabled;
 use crate::sev::{
     init_hypervisor_ghcb_features, pvalidate_range, sev_status_init, sev_status_verify, PvalidateOp,
 };
-use crate::svsm_console::SVSMIOPort;
 use crate::types::PageSize;
 use crate::utils::immut_after_init::ImmutAfterInitCell;
 use crate::utils::MemoryRegion;
 
 use core::sync::atomic::{AtomicU32, Ordering};
 
-static CONSOLE_IO: SVSMIOPort = SVSMIOPort::new();
-static CONSOLE_SERIAL: ImmutAfterInitCell<SerialPort<'_>> = ImmutAfterInitCell::uninit();
+static GHCB_IO_DRIVER: GHCBIOPort = GHCBIOPort::new();
 
 static VTOM: ImmutAfterInitCell<usize> = ImmutAfterInitCell::uninit();
 
@@ -56,11 +56,7 @@ impl SvsmPlatform for SnpPlatform {
     }
 
     fn env_setup_late(&mut self, debug_serial_port: u16) -> Result<(), SvsmError> {
-        CONSOLE_SERIAL
-            .init(&SerialPort::new(&CONSOLE_IO, debug_serial_port))
-            .map_err(|_| SvsmError::Console)?;
-        (*CONSOLE_SERIAL).init();
-        init_console(&*CONSOLE_SERIAL).map_err(|_| SvsmError::Console)?;
+        init_svsm_console(&GHCB_IO_DRIVER, debug_serial_port)?;
         sev_status_verify();
         init_hypervisor_ghcb_features()?;
         Ok(())
@@ -126,7 +122,7 @@ impl SvsmPlatform for SnpPlatform {
     }
 
     fn get_io_port(&self) -> &'static dyn IOPort {
-        &CONSOLE_IO
+        &GHCB_IO_DRIVER
     }
 
     fn page_state_change(
@@ -227,3 +223,59 @@ impl SvsmPlatform for SnpPlatform {
         current_ghcb().ap_create(vmsa_pa, cpu.get_apic_id().into(), 0, sev_features)
     }
 }
+
+#[derive(Clone, Copy, Debug, Default)]
+pub struct GHCBIOPort {}
+
+impl GHCBIOPort {
+    pub const fn new() -> Self {
+        GHCBIOPort {}
+    }
+}
+
+impl IOPort for GHCBIOPort {
+    fn outb(&self, port: u16, value: u8) {
+        let ret = current_ghcb().ioio_out(port, GHCBIOSize::Size8, value as u64);
+        if ret.is_err() {
+            request_termination_msr();
+        }
+    }
+
+    fn inb(&self, port: u16) -> u8 {
+        let ret = current_ghcb().ioio_in(port, GHCBIOSize::Size8);
+        match ret {
+            Ok(v) => (v & 0xff) as u8,
+            Err(_e) => request_termination_msr(),
+        }
+    }
+
+    fn outw(&self, port: u16, value: u16) {
+        let ret = current_ghcb().ioio_out(port, GHCBIOSize::Size16, value as u64);
+        if ret.is_err() {
+            request_termination_msr();
+        }
+    }
+
+    fn inw(&self, port: u16) -> u16 {
+        let ret = current_ghcb().ioio_in(port, GHCBIOSize::Size16);
+        match ret {
+            Ok(v) => (v & 0xffff) as u16,
+            Err(_e) => request_termination_msr(),
+        }
+    }
+
+    fn outl(&self, port: u16, value: u32) {
+        let ret = current_ghcb().ioio_out(port, GHCBIOSize::Size32, value as u64);
+        if ret.is_err() {
+            request_termination_msr();
+        }
+    }
+
+    fn inl(&self, port: u16) -> u32 {
+        let ret = current_ghcb().ioio_in(port, GHCBIOSize::Size32);
+        match ret {
+            Ok(v) => (v & 0xffffffff) as u32,
+            Err(_e) => request_termination_msr(),
+        }
+    }
+}

kernel/src/platform/tdp.rs

@@ -5,23 +5,16 @@
 // Author: Peter Fang <[email protected]>
 
 use crate::address::{PhysAddr, VirtAddr};
-use crate::console::init_console;
+use crate::console::init_svsm_console;
 use crate::cpu::cpuid::CpuidResult;
 use crate::cpu::percpu::PerCpu;
 use crate::error::SvsmError;
-use crate::io::IOPort;
+use crate::io::{IOPort, DEFAULT_IO_DRIVER};
 use crate::platform::{PageEncryptionMasks, PageStateChangeOp, SvsmPlatform};
-use crate::serial::SerialPort;
-use crate::svsm_console::SVSMIOPort;
 use crate::types::PageSize;
 use crate::utils::immut_after_init::ImmutAfterInitCell;
 use crate::utils::MemoryRegion;
 
-// FIXME - SVSMIOPort doesn't work on TDP, but the platform does not yet have
-// an alternative available.
-static CONSOLE_IO: SVSMIOPort = SVSMIOPort::new();
-static CONSOLE_SERIAL: ImmutAfterInitCell<SerialPort<'_>> = ImmutAfterInitCell::uninit();
-
 static VTOM: ImmutAfterInitCell<usize> = ImmutAfterInitCell::uninit();
 
 #[derive(Clone, Copy, Debug)]
@@ -45,11 +38,7 @@ impl SvsmPlatform for TdpPlatform {
     }
 
     fn env_setup_late(&mut self, debug_serial_port: u16) -> Result<(), SvsmError> {
-        CONSOLE_SERIAL
-            .init(&SerialPort::new(&CONSOLE_IO, debug_serial_port))
-            .map_err(|_| SvsmError::Console)?;
-        (*CONSOLE_SERIAL).init();
-        init_console(&*CONSOLE_SERIAL).map_err(|_| SvsmError::Console)
+        init_svsm_console(&DEFAULT_IO_DRIVER, debug_serial_port)
     }
 
     fn env_setup_svsm(&self) -> Result<(), SvsmError> {
@@ -83,7 +72,9 @@ impl SvsmPlatform for TdpPlatform {
     fn setup_guest_host_comm(&mut self, _cpu: &PerCpu, _is_bsp: bool) {}
 
     fn get_io_port(&self) -> &'static dyn IOPort {
-        &CONSOLE_IO
+        // FIXME - the default I/O port implementation doesn't work on TDP,
+        // but the platform does not yet have an alternative available.
+        &DEFAULT_IO_DRIVER
     }
 
     fn page_state_change(