initial import

1 files changed, 239 insertions, 0 deletions

diff --git a/vbox.c b/vbox.c
new file mode 100644
index 0000000..042a470
--- /dev/null
+++ b/vbox.c
@@ -0,0 +1,239 @@
+/*
+ * VBMouse - VirtualBox communication routines
+ * Copyright (C) 2022 Javier S. Pedro
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <windows.h>
+#include <i86.h>
+
+#include "pci.h"
+#include "vboxdev.h"
+#include "vbox.h"
+
+/** VBox's PCI bus, device number, etc. */
+static pcisel vbpci;
+/** IO base of VBox's PCI device. */
+static uint16_t vbiobase;
+/** IRQ number of VBox's PCI device. Unused. */
+static uint8_t vbirq;
+
+/** Keep a pre-allocated VBox VMMDevRequest struct for the benefit of the callbacks,
+    which may be called in a IRQ handler where I'd prefer to avoid making API calls. */
+static VMMDevReqMouseStatus __far * reqMouse;
+static HANDLE reqMouseH;
+static uint32_t reqMouseAddr;
+
+/** Actually send a request to the VirtualBox VMM device.
+  * @param addr 32-bit linear address containing the VMMDevRequest struct.
+  */
+static void vbox_send_request(uint32_t addr);
+#pragma aux vbox_send_request = \
+	"movzx eax, ax" /* Need to make a single 32-bit write so combine both regs. */ \
+	"movzx ebx, bx" \
+	"shl ebx, 16" \
+	"or eax, ebx" \
+	"mov dx, vbiobase" \
+	"out dx, eax" \
+	"shr ebx, 16" \
+	__parm [bx ax] \
+	__modify [dx]
+
+/** Acknowledge an interrupt from the VirtualBox VMM device at iobase.
+ *  @return bitmask with all pending events (e.g. VMMDEV_EVENT_MOUSE_CAPABILITIES_CHANGED). */
+static uint32_t vbox_irq_ack();
+#pragma aux vbox_irq_ack = \
+	"mov dx, vbiobase" \
+	"add dx, 8" \
+	"in eax, dx" \
+	"mov edx, eax" \
+	"shr edx, 16" \
+	__value [dx ax] \
+
+// Classic PCI defines
+#define VBOX_PCI_VEND_ID 0x80ee
+#define VBOX_PCI_PROD_ID 0xcafe
+enum {
+	CFG_COMMAND         = 0x04, /* Word  */
+	CFG_INTERRUPT       = 0x3C, /* Byte */
+	CFG_BAR0            = 0x10, /* DWord */
+	CFG_BAR1            = 0x14, /* DWord */
+};
+
+/** Gets the 32-bit linear address of a 16:16 far pointer.
+    Uses GetSelectorBase() since we are supposed to work under protected mode. */
+static inline uint32_t get_physical_addr(void far *obj)
+{
+	return GetSelectorBase(FP_SEG(obj)) + FP_OFF(obj);
+}
+
+/** Send a request to the VirtualBox VMM device at vbiobase.
+ *  @param request must be a VMMDevRequest (e.g. VMMDevReqMouseStatus). */
+static inline void vbox_request(void far *request)
+{
+	uint32_t addr = get_physical_addr(request);
+	vbox_send_request(addr);
+}
+
+/** Finds the VirtualBox PCI device and reads the current IO base.
+  * @returns 0 if the device was found. */
+int vbox_init(void)
+{
+	int err;
+	uint16_t command;
+	uint32_t bar;
+
+	if ((err = pci_init_bios())) {
+		return -1;
+	}
+
+	if ((err = pci_find_device(&vbpci, VBOX_PCI_VEND_ID, VBOX_PCI_PROD_ID, 0))) {
+		return -1;
+	}
+
+	if ((err = pci_read_config_word(vbpci, CFG_COMMAND, &command))
+	    || !(command & 1)) {
+		return -2;
+	}
+
+	if ((err = pci_read_config_byte(vbpci, CFG_INTERRUPT, &vbirq))) {
+		return -2;
+	}
+
+	if ((err = pci_read_config_dword(vbpci, CFG_BAR0, &bar))) {
+		return -2;
+	}
+
+	if (!(bar & 1)) {
+		return -2;
+	}
+
+	vbiobase = bar & 0xFFFC;
+
+	return 0;
+}
+
+/** Lets VirtualBox know that there are VirtualBox Guest Additions on this guest.
+  * @param osType os installed on this guest. */
+int vbox_report_guest_info(uint32_t osType)
+{
+	VMMDevReportGuestInfo req = {0};
+
+	req.header.size = sizeof(req);
+	req.header.version = VMMDEV_REQUEST_HEADER_VERSION;
+	req.header.requestType = VMMDevReq_ReportGuestInfo;
+	req.header.rc = -1;
+	req.guestInfo.interfaceVersion = VMMDEV_VERSION;
+	req.guestInfo.osType = osType;
+
+	vbox_request(&req);
+
+	return req.header.rc;
+}
+
+/** Tells VirtualBox about the events we are interested in receiving.
+    These events are notified via the PCI IRQ which we are not using, so this is not used either. */
+int vbox_set_filter_mask(uint32_t add, uint32_t remove)
+{
+	VMMDevCtlGuestFilterMask req = {0};
+
+	req.header.size = sizeof(req);
+	req.header.version = VMMDEV_REQUEST_HEADER_VERSION;
+	req.header.requestType = VMMDevReq_CtlGuestFilterMask;
+	req.header.rc = -1;
+	req.u32OrMask = add;
+	req.u32NotMask = remove;
+
+	vbox_request(&req);
+
+	return req.header.rc;
+}
+
+/** Tells VirtualBox whether we want absolute mouse information or not. */
+int vbox_set_mouse(bool enable)
+{
+	VMMDevReqMouseStatus req = {0};
+
+	req.header.size = sizeof(req);
+	req.header.version = VMMDEV_REQUEST_HEADER_VERSION;
+	req.header.requestType = VMMDevReq_SetMouseStatus;
+	req.header.rc = -1;
+	req.mouseFeatures = enable ? VMMDEV_MOUSE_GUEST_CAN_ABSOLUTE : 0;
+
+	vbox_request(&req);
+
+	return req.header.rc;
+}
+
+/** Gets the current absolute mouse position from VirtualBox.
+  * @param abs false if user has disabled mouse integration in VirtualBox,
+  *  in which case we should fallback to PS/2 relative events. */
+int vbox_get_mouse(bool *abs, uint16_t *xpos, uint16_t *ypos)
+{
+	VMMDevReqMouseStatus req = {0};
+
+	req.header.size = sizeof(req);
+	req.header.version = VMMDEV_REQUEST_HEADER_VERSION;
+	req.header.requestType = VMMDevReq_GetMouseStatus;
+	req.header.rc = -1;
+
+	vbox_request(&req);
+
+	*abs = req.mouseFeatures & VMMDEV_MOUSE_HOST_WANTS_ABSOLUTE;
+	*xpos = req.pointerXPos;
+	*ypos = req.pointerYPos;
+
+	return req.header.rc;
+}
+
+/** Just allocates the memory used by vbox_get_mouse_locked below. */
+void vbox_init_callbacks(void)
+{
+	reqMouseH = GlobalAlloc(GMEM_FIXED|GMEM_SHARE, sizeof(VMMDevReqMouseStatus));
+	reqMouse = (LPVOID) GlobalLock(reqMouseH);
+	reqMouseAddr = get_physical_addr(reqMouse);
+}
+
+void vbox_deinit_callbacks(void)
+{
+	GlobalFree(reqMouseH);
+	reqMouse = NULL;
+	reqMouseAddr = 0;
+}
+
+#pragma code_seg ( "CALLBACKS" )
+
+/** This is a version of vbox_get_mouse() that does not call any other functions. */
+int vbox_get_mouse_locked(bool *abs, uint16_t *xpos, uint16_t *ypos)
+{
+	// Note that this may be called with interrupts disabled
+	reqMouse->header.size = sizeof(VMMDevReqMouseStatus);
+	reqMouse->header.version = VMMDEV_REQUEST_HEADER_VERSION;
+	reqMouse->header.requestType = VMMDevReq_GetMouseStatus;
+	reqMouse->header.rc = -1;
+	reqMouse->mouseFeatures = 0;
+	reqMouse->pointerXPos = 0;
+	reqMouse->pointerYPos = 0;
+
+	vbox_send_request(reqMouseAddr);
+
+	*abs = reqMouse->mouseFeatures & VMMDEV_MOUSE_HOST_WANTS_ABSOLUTE;
+	*xpos = reqMouse->pointerXPos;
+	*ypos = reqMouse->pointerYPos;
+
+	return reqMouse->header.rc;
+}
+