From 73822ec806bc8459047b6e9dea71d675c283a84c Mon Sep 17 00:00:00 2001 From: aliguori Date: Thu, 15 Jan 2009 20:11:34 +0000 Subject: Add -rtc-td-hack option to fix time drift with RTC on Windows (Gleb Natapov) After my last patch to fix interrupt coalescing was rejected on the basis that it is too intrusive we decided to make the fix much more localized and only fix the problem for RTC time source. Unfortunately it is impossible to fix the problem entirely inside RTC code like Andrzej proposed since Windows reads RTC register C more then once on each time interrupt so it is impossible to count reliably how many interrupt windows actually handled. Proposed solution is localized to I386 target and is disabled by default. To enable it "-rtc-td-hack" flag should be used. Signed-off-by: Gleb Natapov Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6320 c046a42c-6fe2-441c-8c8c-71466251a162 --- vl.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'vl.c') diff --git a/vl.c b/vl.c index 2e1ce5e956..f0701da6e4 100644 --- a/vl.c +++ b/vl.c @@ -212,6 +212,7 @@ CharDriverState *parallel_hds[MAX_PARALLEL_PORTS]; CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES]; #ifdef TARGET_I386 int win2k_install_hack = 0; +int rtc_td_hack = 0; #endif int usb_enabled = 0; int smp_cpus = 1; @@ -3878,6 +3879,7 @@ static void help(int exitcode) "-full-screen start in full screen\n" #ifdef TARGET_I386 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n" + "-rtc-td-hack use it to fix time drift in Windows ACPI HAL\n" #endif "-usb enable the USB driver (will be the default soon)\n" "-usbdevice name add the host or guest USB device 'name'\n" @@ -4074,6 +4076,7 @@ enum { QEMU_OPTION_kernel_kqemu, QEMU_OPTION_enable_kvm, QEMU_OPTION_win2k_hack, + QEMU_OPTION_rtc_td_hack, QEMU_OPTION_usb, QEMU_OPTION_usbdevice, QEMU_OPTION_smp, @@ -4183,6 +4186,7 @@ static const QEMUOption qemu_options[] = { #endif { "pidfile", HAS_ARG, QEMU_OPTION_pidfile }, { "win2k-hack", 0, QEMU_OPTION_win2k_hack }, + { "rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack }, { "usbdevice", HAS_ARG, QEMU_OPTION_usbdevice }, { "smp", HAS_ARG, QEMU_OPTION_smp }, { "vnc", HAS_ARG, QEMU_OPTION_vnc }, @@ -5011,6 +5015,9 @@ int main(int argc, char **argv, char **envp) case QEMU_OPTION_win2k_hack: win2k_install_hack = 1; break; + case QEMU_OPTION_rtc_td_hack: + rtc_td_hack = 1; + break; #endif #ifdef USE_KQEMU case QEMU_OPTION_no_kqemu: -- cgit v1.2.3