From 814733350edbf2539ff2673b5db3d839b16cb36e Mon Sep 17 00:00:00 2001
From: Chris Guikema <chris.guikema@dornerworks.com>
Date: Wed, 25 Oct 2023 15:44:26 -0400
Subject: [PATCH] init: add hooks for hpet emulation

This allows VMs to emulate the HPET for higher-precision timing.

Signed-off-by: Chris Guikema <chris.guikema@dornerworks.com>
---
 camkes_vm_helpers.cmake      |  1 +
 components/Init/src/main.c   | 18 ++++++++++++++++++
 components/Init/src/timers.h |  5 +++++
 3 files changed, 24 insertions(+)

diff --git a/camkes_vm_helpers.cmake b/camkes_vm_helpers.cmake
index 5aac4647..9f742fa6 100644
--- a/camkes_vm_helpers.cmake
+++ b/camkes_vm_helpers.cmake
@@ -39,6 +39,7 @@ function(DeclareCAmkESVM init_component)
         sel4allocman
         sel4vm
         sel4vmmplatsupport
+        sel4vmmplatsupport_Config
         sel4_autoconf
         camkes_vmm_Config
         virtqueue
diff --git a/components/Init/src/main.c b/components/Init/src/main.c
index 1e726e26..af56b93a 100644
--- a/components/Init/src/main.c
+++ b/components/Init/src/main.c
@@ -34,12 +34,14 @@
 #include <sel4vm/arch/ioports.h>
 #include <sel4vm/guest_irq_controller.h>
 
+#include <sel4vmmplatsupport/gen_config.h>
 #include <sel4vmmplatsupport/guest_memory_util.h>
 #include <sel4vmmplatsupport/ioports.h>
 #include <sel4vmmplatsupport/drivers/pci.h>
 #include <sel4vmmplatsupport/drivers/pci_helper.h>
 #include <sel4vmmplatsupport/drivers/cross_vm_connection.h>
 #include <sel4vmmplatsupport/arch/drivers/vmm_pci_helper.h>
+#include <sel4vmmplatsupport/arch/hpet.h>
 
 #include <sel4vm/arch/vmcall.h>
 
@@ -438,6 +440,7 @@ static device_notify_t *device_notify_list = NULL;
 void pit_timer_interrupt(void);
 void rtc_timer_interrupt(uint32_t);
 void serial_timer_interrupt(uint32_t);
+void hpet_timer_interrupt(uint32_t);
 
 static seL4_Word irq_badges[16] = {
     VM_PIC_BADGE_IRQ_0,
@@ -483,6 +486,11 @@ static int handle_async_event(vm_t *vm, seL4_Word badge, UNUSED seL4_MessageInfo
                                  TIMER_MORE_CHARS))) {
                 serial_timer_interrupt(completed);
             }
+#ifdef CONFIG_VMM_USE_HPET
+            if (completed & (BIT(TIMER_HPET0) | BIT(TIMER_HPET1) | BIT(TIMER_HPET2))) {
+                hpet_timer_interrupt(completed);
+            }
+#endif
         }
         if ((badge & serial_getchar_notification_badge()) == serial_getchar_notification_badge()) {
             serial_character_interrupt();
@@ -698,6 +706,16 @@ void *main_continued(void *arg)
     ZF_LOGI("RTC pre init");
     rtc_pre_init();
 
+#ifdef CONFIG_VMM_USE_HPET
+    ZF_LOGI("HPET pre init\n");
+    uint64_t tsc_frequency = init_timer_tsc_frequency();
+    hpet_pre_init(tsc_frequency,
+                  TIMER_HPET0,
+                  init_timer_oneshot_relative,
+                  init_timer_stop);
+    vm_create_hpet(&vm);
+#endif
+
     error = vmm_io_port_init(&io_ports, FREE_IOPORT_START);
     if (error) {
         ZF_LOGF_IF(error, "Failed to initialise VMM ioport management");
diff --git a/components/Init/src/timers.h b/components/Init/src/timers.h
index 66cc26d6..422c35e6 100644
--- a/components/Init/src/timers.h
+++ b/components/Init/src/timers.h
@@ -24,3 +24,8 @@
 #define TIMER_TRANSMIT_TIMER 6
 #define TIMER_MODEM_STATUS_TIMER 7
 #define TIMER_MORE_CHARS 8
+
+/* hpet timer */
+#define TIMER_HPET0 9
+#define TIMER_HPET1 10
+#define TIMER_HPET2 11