[pvmfw] Extract a library to support various hypervisor backends

This cl extracts a library libhyp from pvmfw to support
various hypervisor backends including kvm.

Bug: 272226230
Test: m pvmfw_img
Change-Id: I5307cb5d6cccc7a01af6bc9c46ae7111c0d51e93
diff --git a/pvmfw/src/hvc.rs b/pvmfw/src/hvc.rs
index f44e26e..6c5017f 100644
--- a/pvmfw/src/hvc.rs
+++ b/pvmfw/src/hvc.rs
@@ -16,9 +16,7 @@
 
 pub mod trng;
 
-use log::info;
-use smccc::{self, checked_hvc64, checked_hvc64_expect_zero};
-
+// TODO(b/272226230): Move all the trng functions to trng module
 const ARM_SMCCC_TRNG_VERSION: u32 = 0x8400_0050;
 #[allow(dead_code)]
 const ARM_SMCCC_TRNG_FEATURES: u32 = 0x8400_0051;
@@ -27,85 +25,6 @@
 #[allow(dead_code)]
 const ARM_SMCCC_TRNG_RND32: u32 = 0x8400_0053;
 const ARM_SMCCC_TRNG_RND64: u32 = 0xc400_0053;
-const ARM_SMCCC_KVM_FUNC_HYP_MEMINFO: u32 = 0xc6000002;
-const ARM_SMCCC_KVM_FUNC_MEM_SHARE: u32 = 0xc6000003;
-const ARM_SMCCC_KVM_FUNC_MEM_UNSHARE: u32 = 0xc6000004;
-const VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID: u32 = 0xc6000005;
-const VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID: u32 = 0xc6000006;
-const VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID: u32 = 0xc6000007;
-const VENDOR_HYP_KVM_MMIO_GUARD_UNMAP_FUNC_ID: u32 = 0xc6000008;
-
-/// Queries the memory protection parameters for a protected virtual machine.
-///
-/// Returns the memory protection granule size in bytes.
-pub fn kvm_hyp_meminfo() -> smccc::Result<u64> {
-    let args = [0u64; 17];
-    checked_hvc64(ARM_SMCCC_KVM_FUNC_HYP_MEMINFO, args)
-}
-
-/// Shares a region of memory with the KVM host, granting it read, write and execute permissions.
-/// The size of the region is equal to the memory protection granule returned by [`hyp_meminfo`].
-pub fn kvm_mem_share(base_ipa: u64) -> smccc::Result<()> {
-    let mut args = [0u64; 17];
-    args[0] = base_ipa;
-
-    checked_hvc64_expect_zero(ARM_SMCCC_KVM_FUNC_MEM_SHARE, args)
-}
-
-/// Revokes access permission from the KVM host to a memory region previously shared with
-/// [`mem_share`]. The size of the region is equal to the memory protection granule returned by
-/// [`hyp_meminfo`].
-pub fn kvm_mem_unshare(base_ipa: u64) -> smccc::Result<()> {
-    let mut args = [0u64; 17];
-    args[0] = base_ipa;
-
-    checked_hvc64_expect_zero(ARM_SMCCC_KVM_FUNC_MEM_UNSHARE, args)
-}
-
-pub fn kvm_mmio_guard_info() -> smccc::Result<u64> {
-    let args = [0u64; 17];
-
-    checked_hvc64(VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID, args)
-}
-
-pub fn kvm_mmio_guard_enroll() -> smccc::Result<()> {
-    let args = [0u64; 17];
-
-    checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID, args)
-}
-
-pub fn kvm_mmio_guard_map(ipa: u64) -> smccc::Result<()> {
-    let mut args = [0u64; 17];
-    args[0] = ipa;
-
-    // TODO(b/277859415): pKVM returns a i32 instead of a i64 in T.
-    // Drop this hack once T reaches EoL.
-    let is_i32_error_code = |n| u32::try_from(n).ok().filter(|v| (*v as i32) < 0).is_some();
-    match checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID, args) {
-        Err(smccc::Error::Unexpected(e)) if is_i32_error_code(e) => {
-            info!("Handled a pKVM bug by interpreting the MMIO_GUARD_MAP return value as i32");
-            match e as u32 as i32 {
-                -1 => Err(smccc::Error::NotSupported),
-                -2 => Err(smccc::Error::NotRequired),
-                -3 => Err(smccc::Error::InvalidParameter),
-                ret => Err(smccc::Error::Unknown(ret as i64)),
-            }
-        }
-        res => res,
-    }
-}
-
-pub fn kvm_mmio_guard_unmap(ipa: u64) -> smccc::Result<()> {
-    let mut args = [0u64; 17];
-    args[0] = ipa;
-
-    // TODO(b/277860860): pKVM returns NOT_SUPPORTED for SUCCESS in T.
-    // Drop this hack once T reaches EoL.
-    match checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_UNMAP_FUNC_ID, args) {
-        Err(smccc::Error::NotSupported) | Ok(_) => Ok(()),
-        x => x,
-    }
-}
 
 /// Returns the (major, minor) version tuple, as defined by the SMCCC TRNG.
 pub fn trng_version() -> trng::Result<(u16, u16)> {