hv: emulate reset register 0xcf9 and 0x64

- post-launched RTVM: intercept both PIO ports so that hypervisor has a
  chance to set VM_POWERING_OFF flag.
- all other type of VMs: deny these 2 ports from guest access so that
  guests are not able to reset host.

Tracked-On: #2700
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: ZideChen0

hypervisor/arch/x86/guest/vm.c

@@ -8,6 +8,7 @@
 #include <errno.h>
 #include <sprintf.h>
 #include <vm.h>
+#include <vm_reset.h>
 #include <bits.h>
 #include <e820.h>
 #include <multiboot.h>
@@ -423,6 +424,8 @@ int32_t create_vm(uint16_t vm_id, struct acrn_vm_config *vm_config, struct acrn_
 
 		vpci_init(vm);
 
+		register_reset_port_handler(vm);
+
 		/* vpic wire_mode default is INTR */
 		vm->wire_mode = VPIC_WIRE_INTR;
 

hypervisor/arch/x86/guest/vm_reset.c

@@ -5,8 +5,102 @@
  */
 
 #include <vm.h>
-#include <vm_reset.h>
+#include <io.h>
+#include <logmsg.h>
 #include <per_cpu.h>
+#include <vm_reset.h>
+
+/**
+ * @pre vcpu != NULL && vm != NULL
+ */
+static bool handle_reset_reg_read(struct acrn_vm *vm, struct acrn_vcpu *vcpu, __unused uint16_t addr,
+		__unused size_t bytes)
+{
+	bool ret = true;
+
+	if (is_postlaunched_vm(vm)) {
+		/* re-inject to DM */
+		ret = false;
+	} else {
+		/*
+		 * - keyboard control/status register 0x64: ACRN doesn't expose kbd controller to the guest.
+		 * - reset control register 0xcf9: hide this from guests for now.
+		 */
+		vcpu->req.reqs.pio.value = ~0U;
+	}
+
+	return ret;
+}
+
+/**
+ * @pre vm != NULL
+ */
+static bool handle_common_reset_reg_write(struct acrn_vm *vm, bool reset)
+{
+	bool ret = true;
+
+	if (is_postlaunched_vm(vm)) {
+		/* re-inject to DM */
+		ret = false;
+
+		if (reset && is_rt_vm(vm)) {
+			vm->state = VM_POWERING_OFF;
+		}
+	} else {
+		/*
+		 * ignore writes from SOS or pre-launched VMs.
+		 * equivalent to hide this port from guests.
+		 */
+	}
+
+	return ret;
+}
+
+/**
+ * @pre vm != NULL
+ */
+static bool handle_kb_write(struct acrn_vm *vm, __unused uint16_t addr, size_t bytes, uint32_t val)
+{
+	/* ignore commands other than system reset */
+	return handle_common_reset_reg_write(vm, ((bytes == 1U) && (val == 0xfeU)));
+}
+
+/*
+ * Reset Control register at I/O port 0xcf9.
+ *     Bit 1 - 0: "soft" reset. Force processor begin execution at power-on reset vector.
+ *             1: "hard" reset. e.g. assert PLTRST# (if implemented) to do a host reset.
+ *     Bit 2 - initiates a system reset when it transitions from 0 to 1.
+ *     Bit 3 - 1: full reset (aka code reset), SLP_S3#/4#/5# or similar pins are asserted for full power cycle.
+ *             0: will be dropped if system in S3/S4/S5.
+ */
+/**
+ * @pre vm != NULL
+ */
+static bool handle_cf9_write(struct acrn_vm *vm, __unused uint16_t addr, size_t bytes, uint32_t val)
+{
+	/* We don't differentiate among hard/soft/warm/cold reset */
+	return handle_common_reset_reg_write(vm, ((bytes == 1U) && ((val & 0x4U) == 0x4U) && ((val & 0xaU) != 0U)));
+}
+
+/**
+ * @pre vm != NULL
+ */
+void register_reset_port_handler(struct acrn_vm *vm)
+{
+	/* Don't support SOS and pre-launched VM re-launch for now. */
+	if (!is_postlaunched_vm(vm) || is_rt_vm(vm)) {
+		struct vm_io_range io_range = {
+			.flags = IO_ATTR_RW,
+			.len = 1U
+		};
+
+		io_range.base = 0x64U;
+		register_pio_emulation_handler(vm, KB_PIO_IDX, &io_range, handle_reset_reg_read, handle_kb_write);
+
+		io_range.base = 0xcf9U;
+		register_pio_emulation_handler(vm, CF9_PIO_IDX, &io_range, handle_reset_reg_read, handle_cf9_write);
+	}
+}
 
 void shutdown_vm_from_idle(uint16_t pcpu_id)
 {

hypervisor/include/arch/x86/guest/vm_reset.h

@@ -7,6 +7,7 @@
 #ifndef VM_RESET_H_
 #define VM_RESET_H_
 
+void register_reset_port_handler(struct acrn_vm *vm);
 void shutdown_vm_from_idle(uint16_t pcpu_id);
 
 #endif /* VM_RESET_H_ */

hypervisor/include/arch/x86/guest/vmx_io.h

@@ -24,7 +24,9 @@
 #define PM1B_CNT_PIO_IDX		(PM1B_EVT_PIO_IDX + 1U)
 #define RTC_PIO_IDX			(PM1B_CNT_PIO_IDX + 1U)
 #define VIRTUAL_PM1A_CNT_PIO_IDX	(RTC_PIO_IDX + 1U)
-#define EMUL_PIO_IDX_MAX		(VIRTUAL_PM1A_CNT_PIO_IDX + 1U)
+#define KB_PIO_IDX			(VIRTUAL_PM1A_CNT_PIO_IDX + 1U)
+#define CF9_PIO_IDX			(KB_PIO_IDX + 1U)
+#define EMUL_PIO_IDX_MAX		(CF9_PIO_IDX + 1U)
 
 /**
  * @brief The handler of VM exits on I/O instructions