[WIP] virtio: detect PIIX4 and attempt to power off via ACPI hack (broken)

bindings/GNUmakefile

@@ -50,7 +50,7 @@ virtio_SRCS := virtio/boot.S virtio/start.c $(common_SRCS) \
     virtio/platform.c virtio/platform_intr.c \
     virtio/pci.c virtio/serial.c virtio/time.c virtio/virtio_ring.c \
     virtio/virtio_net.c virtio/virtio_blk.c virtio/tscclock.c \
-    virtio/clock_subr.c virtio/pvclock.c 
+    virtio/clock_subr.c virtio/pvclock.c virtio/acpi.c
 
 muen_SRCS := muen/start.c $(common_SRCS) $(common_hvt_SRCS) \
     muen/channel.c muen/reader.c muen/writer.c muen/muen-block.c \

bindings/virtio/acpi.c

@@ -0,0 +1,301 @@
+/*
+ * Copyright (c) 2015-2019 Contributors as noted in the AUTHORS file
+ *
+ * This file is part of Solo5, a sandboxed execution environment.
+ *
+ * Permission to use, copy, modify, and/or distribute this software
+ * for any purpose with or without fee is hereby granted, provided
+ * that the above copyright notice and this permission notice appear
+ * in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* This is not a full ACPI implementation.
+
+   A full ACPI implementation involves a turing incomplete byte-code interpreter
+   of third party code with full access to the system.  This is controversial,
+   to say the least.  This implementation may be just enough to shut down a
+   running system.
+   */
+
+#include "bindings.h"
+
+bool acpi_detected = false;
+
+/* This was adapted from kaworu's example in
+https://forum.osdev.org/viewtopic.php?t=16990 */
+
+#define byte uint8_t
+#define word uint16_t
+#define dword uint32_t
+
+dword SMI_CMD;
+byte ACPI_ENABLE;
+byte ACPI_DISABLE;
+dword PM1a_CNT;
+dword PM1b_CNT;
+word SLP_TYPa;
+word SLP_TYPb;
+word SLP_EN;
+word SCI_EN;
+byte PM1_CNT_LEN;
+
+struct RSDPtr {
+   byte Signature[8];
+   byte CheckSum;
+   byte OemID[6];
+   byte Revision;
+   dword *RsdtAddress;
+};
+
+struct FACP {
+   byte Signature[4];
+   dword Length;
+   byte unneded1[40 - 8];
+   dword *DSDT;
+   byte unneded2[48 - 44];
+   dword SMI_CMD;
+   byte ACPI_ENABLE;
+   byte ACPI_DISABLE;
+   byte unneded3[64 - 54];
+   dword PM1a_CNT_BLK;
+   dword PM1b_CNT_BLK;
+   byte unneded4[89 - 72];
+   byte PM1_CNT_LEN;
+};
+
+/* check if the given address has a valid header */
+static unsigned int *acpi_check_rsdptr(unsigned int *ptr)
+{
+    char *sig = "RSD PTR ";
+    struct RSDPtr *rsdp = (struct RSDPtr *) ptr;
+    byte *bptr;
+    byte check = 0;
+    uint32_t i;
+
+    if (memcmp(sig, rsdp, 8) == 0) {
+        // check checksum rsdpd
+        bptr = (byte *) ptr;
+        for (i=0; i<sizeof(struct RSDPtr); i++) {
+            check += *bptr;
+            bptr++;
+        }
+        // found valid rsdpd
+        if (check == 0) {
+            return (unsigned int *) rsdp->RsdtAddress;
+        }
+    }
+    return NULL;
+}
+
+/* finds the acpi header and returns the address of the rsdt */
+static unsigned int *acpi_get_rsdptr(void)
+{
+    uint32_t *addr;
+    uint32_t *rsdp;
+
+    /* search below the 1mb mark for RSDP signature */
+    for (addr = (uint32_t *) 0x000E0000; addr < (uint32_t *)0x00100000; addr += 0x10/sizeof(addr)) {
+        rsdp = acpi_check_rsdptr(addr);
+        if (rsdp != NULL)
+            return rsdp;
+    }
+    /* at address 0x40:0x0E is the RM segment of the ebda */
+    uint32_t *ebda = (uint32_t *)((0x40E * 0x10) & 0x000FFFFF);   // transform segment into linear address
+
+    /* search Extended BIOS Data Area for the Root System Description Pointer signature */
+    for (addr = ebda; addr < (uint32_t *)ebda+1024; addr+= 0x10/sizeof(addr)) {
+        rsdp = acpi_check_rsdptr(addr);
+        if (rsdp != NULL)
+            return rsdp;
+    }
+    return NULL;
+}
+
+/* checks for a given header and validates checksum */
+static int acpi_check_header(uint32_t *ptr, char *sig)
+{
+   if (memcmp(ptr, sig, 4) == 0) {
+      char *checkPtr = (char *)ptr;
+      int len = *(ptr + 1);
+      char check = 0;
+      while (0 < len--) {
+         check += *checkPtr;
+         checkPtr++;
+      }
+      if (check == 0)
+         return 0;
+   }
+   return -1;
+}
+
+static int acpi_enable(void)
+{
+    log(INFO, "Solo5: acpi_enable\n");
+    if ((inw(PM1a_CNT) & SCI_EN) == 0) {
+        /* check if acpi can be enabled */
+        if (SMI_CMD != 0 && ACPI_ENABLE != 0) {
+            outb(SMI_CMD, ACPI_ENABLE); /* send acpi enable command */
+            /* give 3 seconds time to enable acpi */
+            cpu_wasteful_milli_sleep(3000);
+            int i = 0;
+            if (PM1b_CNT != 0) {
+                for (; i<300; i++ ) {
+                  if ( (inw((unsigned int)PM1b_CNT) &SCI_EN) == 1 )
+                      break;
+                  cpu_wasteful_milli_sleep(10);
+                }
+            }
+            if (i<300) {
+                log(INFO, "Solo5: enabled ACPI\n");
+                return 0;
+            } else {
+                log(INFO, "Solo5: timed out trying to enable ACPI\n");
+                return -1;
+            }
+        } else {
+            log(INFO, "Solo5: no known way to enable ACPI.\n");
+            return -1;
+          }
+    } else {
+        log(INFO, "Solo5: ACPI was already enabled\n");
+        return 0;
+    }
+}
+
+
+//
+// bytecode of the \_S5 object
+// -----------------------------------------
+//        | (optional) |    |    |    |
+// NameOP | \          | _  | S  | 5  | _
+// 08     | 5A         | 5F | 53 | 35 | 5F
+//
+// -----------------------------------------------------------------------------------------------------------
+//           |           |              | ( SLP_TYPa   ) | ( SLP_TYPb   ) | ( Reserved   ) | (Reserved    )
+// PackageOP | PkgLength | NumElements  | byteprefix Num | byteprefix Num | byteprefix Num | byteprefix Num
+// 12        | 0A        | 04           | 0A         05  | 0A          05 | 0A         05  | 0A         05
+//
+//----this-structure-was-also-seen----------------------
+// PackageOP | PkgLength | NumElements |
+// 12        | 06        | 04          | 00 00 00 00
+//
+// (Pkglength bit 6-7 encode additional PkgLength bytes [shouldn't be the case here])
+//
+static int acpi_init(void)
+{
+    log(INFO, "Solo5: acpi_init()\n");
+    uint32_t *ptr = acpi_get_rsdptr();
+    int entrys;
+
+    if (ptr == NULL) {
+        log(WARN, "Solo5: no rsdptr\n");
+        return -1;
+    }
+    if (acpi_check_header(ptr, "RSDT") != 0) {
+        log(WARN, "Solo5: RSDT not found\n");
+        return -1;
+    }
+    // the RSDT contains an unknown number of pointers to acpi tables
+    entrys = *(ptr + 1);
+    entrys = (entrys-36) /4;
+    ptr += 36/4;   // skip header information
+    log(INFO, "Solo5: %d ACPI table entries\n", entrys);
+    while (0<entrys--)
+    {
+        // check if the desired table is reached
+        log(WARN, "Solo5: ACPI ptr first char: %c\n", *((char *)ptr));
+        uint32_t *pptr = (uint32_t *)((uintptr_t)(*ptr));
+        if (acpi_check_header(pptr, "FACP") == 0) {
+          entrys = -2;
+          struct FACP *facp = (struct FACP *)pptr;
+          if (acpi_check_header((unsigned int *) facp->DSDT, "DSDT") == 0)
+          {
+              // search the \_S5 package in the DSDT
+              char *S5Addr = (char *) facp->DSDT +36; // skip header
+              int dsdtLength = *(facp->DSDT+1) -36;
+              while (0 < dsdtLength--) {
+                if (memcmp(S5Addr, "_S5_", 4) == 0)
+                    break;
+                S5Addr++;
+              }
+              // check if \_S5 was found
+              if (dsdtLength > 0)
+              {
+                // check for valid AML structure
+                if ( (*(S5Addr-1) == 0x08
+                      || ( *(S5Addr-2) == 0x08 && *(S5Addr-1) == '\\') )
+                    && *(S5Addr+4) == 0x12 ) {
+                    S5Addr += 5;
+                    S5Addr += ((*S5Addr &0xC0)>>6) +2;   // calculate PkgLength size
+
+                    if (*S5Addr == 0x0A)
+                      S5Addr++;   // skip byteprefix
+                    SLP_TYPa = *(S5Addr)<<10;
+                    S5Addr++;
+
+                    if (*S5Addr == 0x0A)
+                      S5Addr++;   // skip byteprefix
+                    SLP_TYPb = *(S5Addr)<<10;
+
+                    SMI_CMD = facp->SMI_CMD;
+
+                    ACPI_ENABLE = facp->ACPI_ENABLE;
+                    ACPI_DISABLE = facp->ACPI_DISABLE;
+
+                    PM1a_CNT = facp->PM1a_CNT_BLK;
+                    PM1b_CNT = facp->PM1b_CNT_BLK;
+
+                    PM1_CNT_LEN = facp->PM1_CNT_LEN;
+
+                    SLP_EN = 1<<13;
+                    SCI_EN = 1;
+
+                    return 0;
+                } else {
+                    log(WARN, "Solo5: \\_S5 parse error.\n");
+                }
+              } else {
+                log(WARN, "Solo5: \\_S5 not present.\n");
+              }
+          } else {
+              log(WARN, "Solo5: DSDT invalid.\n");
+          }
+        }
+        ptr++;
+    }
+    log(INFO, "Solo5: no valid FACP present.\n");
+    return -1;
+}
+
+void acpi_poweroff(void)
+{
+    log(INFO, "Solo5: ACPI poweroff initiated\n");
+    if (!acpi_detected) {
+        log(WARN, "Solo5: acpi_poweroff() called but ACPI poweroff is not available?\n");
+        return;
+    }
+    log(INFO, "Solo5: init ACPI\n");
+    acpi_init();
+    /* SCI_EN is set to 1 if acpi shutdown is possible */
+    if (SCI_EN == 0) {
+        log(WARN, "Solo5: ACPI shutdown is not possible (SCI_EN == 0)\n");
+        return;
+    }
+    log(WARN, "Solo5: initiating ACPI poweroff\n");
+    acpi_enable();
+    /* send the shutdown command */
+    outw(PM1a_CNT, SLP_TYPa | SLP_EN );
+    if (PM1b_CNT != 0)
+      outw(PM1b_CNT, SLP_TYPb | SLP_EN);
+
+    log(WARN, "Solo5: ACPI poweroff failed.\n");
+}

bindings/virtio/bindings.h

@@ -48,17 +48,23 @@ int tscclock_init(void);
 uint64_t tscclock_monotonic(void);
 uint64_t tscclock_epochoffset(void);
 void cpu_block(uint64_t until);
+void cpu_wasteful_milli_sleep(uint64_t millis);
 
-/* pci.c: only enumerate for now */
+/* pci.c: only enumerate for now (except with a hack for poweroff). */
 struct pci_config_info {
     uint8_t bus;
     uint8_t dev;
+    uint8_t fun;
     uint16_t vendor_id;
+    uint16_t device_id;
     uint16_t subsys_id;
     uint16_t base;
     uint8_t irq;
 };
 
+extern bool acpi_detected;
+void acpi_poweroff(void);
+
 void pci_enumerate(void);
 
 /* virtio.c: mostly net for now */