diff options
Diffstat (limited to 'x86_64/src')
| -rw-r--r-- | x86_64/src/cpuid.rs | 35 | ||||
| -rw-r--r-- | x86_64/src/lib.rs | 3 | ||||
| -rw-r--r-- | x86_64/src/regs.rs | 107 |
3 files changed, 140 insertions, 5 deletions
diff --git a/x86_64/src/cpuid.rs b/x86_64/src/cpuid.rs index 9f76550..5710120 100644 --- a/x86_64/src/cpuid.rs +++ b/x86_64/src/cpuid.rs @@ -121,6 +121,41 @@ pub fn setup_cpuid(kvm: &kvm::Kvm, vcpu: &kvm::Vcpu, cpu_id: u64, nrcpus: u64) - .map_err(Error::SetSupportedCpusFailed) } +/// get host cpu max physical address bits +pub fn phy_max_address_bits() -> u32 { + let mut eax: u32 = 0; + let mut ebx: u32 = 0; + let mut ecx: u32 = 0; + let mut edx: u32 = 0; + let mut phys_bits: u32 = 36; + + unsafe { + host_cpuid( + 0x80000000, + 0, + &mut eax as *mut u32, + &mut ebx as *mut u32, + &mut ecx as *mut u32, + &mut edx as *mut u32, + ); + } + if eax >= 0x80000008 { + unsafe { + host_cpuid( + 0x80000008, + 0, + &mut eax as *mut u32, + &mut ebx as *mut u32, + &mut ecx as *mut u32, + &mut edx as *mut u32, + ); + } + phys_bits = eax & 0xff; + } + + phys_bits +} + #[cfg(test)] mod tests { use super::*; diff --git a/x86_64/src/lib.rs b/x86_64/src/lib.rs index 158a11c..172a504 100644 --- a/x86_64/src/lib.rs +++ b/x86_64/src/lib.rs @@ -157,6 +157,7 @@ impl std::error::Error for Error {} pub struct X8664arch; const BOOT_STACK_POINTER: u64 = 0x8000; +// Make sure it align to 256MB for MTRR convenient const MEM_32BIT_GAP_SIZE: u64 = (768 << 20); const FIRST_ADDR_PAST_32BITS: u64 = (1 << 32); const END_ADDR_BEFORE_32BITS: u64 = FIRST_ADDR_PAST_32BITS - MEM_32BIT_GAP_SIZE; @@ -758,7 +759,7 @@ impl X8664arch { ) -> Result<()> { let kernel_load_addr = GuestAddress(KERNEL_START_OFFSET); cpuid::setup_cpuid(kvm, vcpu, cpu_id, num_cpus).map_err(Error::SetupCpuid)?; - regs::setup_msrs(vcpu).map_err(Error::SetupMsrs)?; + regs::setup_msrs(vcpu, END_ADDR_BEFORE_32BITS).map_err(Error::SetupMsrs)?; let kernel_end = guest_mem .checked_offset(kernel_load_addr, KERNEL_64BIT_ENTRY_OFFSET) .ok_or(Error::KernelOffsetPastEnd)?; diff --git a/x86_64/src/regs.rs b/x86_64/src/regs.rs index 8879a0c..344878a 100644 --- a/x86_64/src/regs.rs +++ b/x86_64/src/regs.rs @@ -13,7 +13,7 @@ use kvm_sys::kvm_msr_entry; use kvm_sys::kvm_msrs; use kvm_sys::kvm_regs; use kvm_sys::kvm_sregs; -use sys_util::{self, GuestAddress, GuestMemory, LayoutAllocation}; +use sys_util::{self, warn, GuestAddress, GuestMemory, LayoutAllocation}; use crate::gdt; @@ -65,7 +65,102 @@ impl Display for Error { } } -fn create_msr_entries() -> Vec<kvm_msr_entry> { +const MTRR_MEMTYPE_UC: u8 = 0x0; +const MTRR_MEMTYPE_WB: u8 = 0x6; +const MTRR_VAR_VALID: u64 = 0x800; +const MTRR_ENABLE: u64 = 0x800; +const MTRR_PHYS_BASE_MSR: u32 = 0x200; +const MTRR_PHYS_MASK_MSR: u32 = 0x201; +const VAR_MTRR_NUM_MASK: u64 = 0xFF; + +// Returns the value of the highest bit in a 64-bit value. Equivalent to +// 1 << HighBitSet(x) +fn get_power_of_two(data: u64) -> u64 { + 1 << (64 - data.leading_zeros() - 1) +} + +// Returns the max length which suitable for mtrr setting based on the +// specified (base, len) +fn get_max_len(base: u64, len: u64) -> u64 { + let mut ret = get_power_of_two(len); + + while base % ret != 0 { + ret >>= 1; + } + + ret +} + +// For the specified (Base, Len), returns (base, len) pair which could be +// set into mtrr register. mtrr requires: the base-address alignment value can't be +// less than its length +fn get_mtrr_pairs(base: u64, len: u64) -> Vec<(u64, u64)> { + let mut vecs = Vec::new(); + + let mut remains = len; + let mut new = base; + while remains != 0 { + let max = get_max_len(new, remains); + vecs.push((new, max)); + remains -= max; + new += max; + } + + vecs +} + +fn create_mtrr_entries(vpu: &kvm::Vcpu, pci_start: u64) -> Vec<kvm_msr_entry> { + let mut entries = Vec::<kvm_msr_entry>::new(); + + // Get VAR MTRR num from MSR_MTRRcap + let mut msrs = vec![kvm_msr_entry { + index: crate::msr_index::MSR_MTRRcap, + ..Default::default() + }]; + if vpu.get_msrs(&mut msrs).is_err() { + warn!("get msrs fail, guest with pass through device may be very slow"); + return entries; + } + let var_num = msrs[0].data & VAR_MTRR_NUM_MASK; + + // Set pci_start .. 4G as UC + // all others are set to default WB + let pci_len = (1 << 32) - pci_start; + let vecs = get_mtrr_pairs(pci_start, pci_len); + if vecs.len() as u64 > var_num { + warn!( + "mtrr fail for pci mmio, please check pci_start addr, + guest with pass through device may be very slow" + ); + return entries; + } + + let phys_mask: u64 = (1 << crate::cpuid::phy_max_address_bits()) - 1; + for (idx, (base, len)) in vecs.iter().enumerate() { + let reg_idx = idx as u32 * 2; + entries.push(kvm_msr_entry { + index: MTRR_PHYS_BASE_MSR + reg_idx, + data: base | MTRR_MEMTYPE_UC as u64, + ..Default::default() + }); + let mask: u64 = len.wrapping_neg() & phys_mask | MTRR_VAR_VALID; + entries.push(kvm_msr_entry { + index: MTRR_PHYS_MASK_MSR + reg_idx, + data: mask, + ..Default::default() + }); + } + // Disable fixed MTRRs and enable variable MTRRs, set default type as WB + entries.push(kvm_msr_entry { + index: crate::msr_index::MSR_MTRRdefType, + data: MTRR_ENABLE | MTRR_MEMTYPE_WB as u64, + ..Default::default() + }); + + entries +} + +fn create_msr_entries(vcpu: &kvm::Vcpu, pci_start: u64) -> Vec<kvm_msr_entry> { let mut entries = Vec::<kvm_msr_entry>::new(); entries.push(kvm_msr_entry { @@ -121,6 +216,10 @@ fn create_msr_entries() -> Vec<kvm_msr_entry> { ..Default::default() }); + let mut mtrr_entries = create_mtrr_entries(vcpu, pci_start); + + entries.append(&mut mtrr_entries); + entries } @@ -129,14 +228,14 @@ fn create_msr_entries() -> Vec<kvm_msr_entry> { /// # Arguments /// /// * `vcpu` - Structure for the vcpu that holds the vcpu fd. -pub fn setup_msrs(vcpu: &kvm::Vcpu) -> Result<()> { +pub fn setup_msrs(vcpu: &kvm::Vcpu, pci_start: u64) -> Result<()> { const SIZE_OF_MSRS: usize = mem::size_of::<kvm_msrs>(); const SIZE_OF_ENTRY: usize = mem::size_of::<kvm_msr_entry>(); const ALIGN_OF_MSRS: usize = mem::align_of::<kvm_msrs>(); const ALIGN_OF_ENTRY: usize = mem::align_of::<kvm_msr_entry>(); const_assert!(ALIGN_OF_MSRS >= ALIGN_OF_ENTRY); - let entry_vec = create_msr_entries(); + let entry_vec = create_msr_entries(vcpu, pci_start); let size = SIZE_OF_MSRS + entry_vec.len() * SIZE_OF_ENTRY; let layout = Layout::from_size_align(size, ALIGN_OF_MSRS).expect("impossible layout"); let mut allocation = LayoutAllocation::zeroed(layout); |