From e9845f0985f088dd01790f4821026df0afba5795 Mon Sep 17 00:00:00 2001 From: Vincenzo Maffione Date: Fri, 2 Aug 2013 18:30:52 +0200 Subject: e1000: add interrupt mitigation support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch partially implements the e1000 interrupt mitigation mechanisms. Using a single QEMUTimer, it emulates the ITR register (which is the newer mitigation register, recommended by Intel) and approximately emulates RADV and TADV registers. TIDV and RDTR register functionalities are not emulated (RDTR is only used to validate RADV, according to the e1000 specs). RADV, TADV, TIDV and RDTR registers make up the older e1000 mitigation mechanism and would need a timer each to be completely emulated. However, a single timer has been used in order to reach a good compromise between emulation accuracy and simplicity/efficiency. The implemented mechanism can be enabled/disabled specifying the command line e1000-specific boolean parameter "mitigation", e.g. qemu-system-x86_64 -device e1000,mitigation=on,... ... For more information, see the Software developer's manual at http://download.intel.com/design/network/manuals/8254x_GBe_SDM.pdf. Interrupt mitigation boosts performance when the guest suffers from an high interrupt rate (i.e. receiving short UDP packets at high packet rate). For some numerical results see the following link http://info.iet.unipi.it/~luigi/papers/20130520-rizzo-vm.pdf Signed-off-by: Vincenzo Maffione Reviewed-by: Andreas Färber (for pc-* machines) Signed-off-by: Stefan Hajnoczi --- hw/i386/pc_piix.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'hw/i386/pc_piix.c') diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 275e395..147d08c 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -339,14 +339,25 @@ static void pc_xen_hvm_init(QEMUMachineInitArgs *args) .desc = "Standard PC (i440FX + PIIX, 1996)", \ .hot_add_cpu = pc_hot_add_cpu +#define PC_I440FX_1_7_MACHINE_OPTIONS PC_I440FX_MACHINE_OPTIONS +static QEMUMachine pc_i440fx_machine_v1_7 = { + PC_I440FX_1_7_MACHINE_OPTIONS, + .name = "pc-i440fx-1.7", + .alias = "pc", + .init = pc_init_pci, + .is_default = 1, +}; + #define PC_I440FX_1_6_MACHINE_OPTIONS PC_I440FX_MACHINE_OPTIONS static QEMUMachine pc_i440fx_machine_v1_6 = { PC_I440FX_1_6_MACHINE_OPTIONS, .name = "pc-i440fx-1.6", - .alias = "pc", .init = pc_init_pci_1_6, - .is_default = 1, + .compat_props = (GlobalProperty[]) { + PC_COMPAT_1_6, + { /* end of list */ } + }, }; static QEMUMachine pc_i440fx_machine_v1_5 = { @@ -735,6 +746,7 @@ static QEMUMachine xenfv_machine = { static void pc_machine_init(void) { + qemu_register_machine(&pc_i440fx_machine_v1_7); qemu_register_machine(&pc_i440fx_machine_v1_6); qemu_register_machine(&pc_i440fx_machine_v1_5); qemu_register_machine(&pc_i440fx_machine_v1_4); -- cgit v1.1