From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- Documentation/ABI/testing/sysfs-tty | 166 ++++++++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-tty (limited to 'Documentation/ABI/testing/sysfs-tty') diff --git a/Documentation/ABI/testing/sysfs-tty b/Documentation/ABI/testing/sysfs-tty new file mode 100644 index 000000000..895c47f05 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-tty @@ -0,0 +1,166 @@ +What: /sys/class/tty/console/active +Date: Nov 2010 +Contact: Kay Sievers +Description: + Shows the list of currently configured + console devices, like 'tty1 ttyS0'. + The last entry in the file is the active + device connected to /dev/console. + The file supports poll() to detect virtual + console switches. + +What: /sys/class/tty/tty/active +Date: Nov 2010 +Contact: Kay Sievers +Description: + Shows the currently active virtual console + device, like 'tty1'. + The file supports poll() to detect virtual + console switches. + +What: /sys/class/tty/ttyS/uartclk +Date: Sep 2012 +Contact: Tomas Hlavacek +Description: + Shows the current uartclk value associated with the + UART port in serial_core, that is bound to TTY like ttyS0. + uartclk = 16 * baud_base + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/type +Date: October 2012 +Contact: Alan Cox +Description: + Shows the current tty type for this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/line +Date: October 2012 +Contact: Alan Cox +Description: + Shows the current tty line number for this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/port +Date: October 2012 +Contact: Alan Cox +Description: + Shows the current tty port I/O address for this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/irq +Date: October 2012 +Contact: Alan Cox +Description: + Shows the current primary interrupt for this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/flags +Date: October 2012 +Contact: Alan Cox +Description: + Show the tty port status flags for this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/xmit_fifo_size +Date: October 2012 +Contact: Alan Cox +Description: + Show the transmit FIFO size for this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/close_delay +Date: October 2012 +Contact: Alan Cox +Description: + Show the closing delay time for this port in centiseconds. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/closing_wait +Date: October 2012 +Contact: Alan Cox +Description: + Show the close wait time for this port in centiseconds. + + Waiting forever is represented as 0. If waiting on close is + disabled then the value is 65535. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/custom_divisor +Date: October 2012 +Contact: Alan Cox +Description: + Show the custom divisor if any that is set on this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/io_type +Date: October 2012 +Contact: Alan Cox +Description: + Show the I/O type that is to be used with the iomem base + address. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/iomem_base +Date: October 2012 +Contact: Alan Cox +Description: + The I/O memory base for this port. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/iomem_reg_shift +Date: October 2012 +Contact: Alan Cox +Description: + Show the register shift indicating the spacing to be used + for accesses on this iomem address. + + These sysfs values expose the TIOCGSERIAL interface via + sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS/rx_trig_bytes +Date: May 2014 +Contact: Yoshihiro YUNOMAE +Description: + Shows current RX interrupt trigger bytes or sets the + user specified value to change it for the FIFO buffer. + Users can show or set this value regardless of opening the + serial device file or not. + + The RX trigger can be set one of four kinds of values for UART + serials. When users input a meaning less value to this I/F, + the RX trigger is changed to the nearest lower value for the + device specification. For example, when user sets 7bytes on + 16550A, which has 1/4/8/14 bytes trigger, the RX trigger is + automatically changed to 4 bytes. + +What: /sys/class/tty/ttyS/console +Date: February 2020 +Contact: Andy Shevchenko +Description: + Allows user to detach or attach back the given device as + kernel console. It shows and accepts a boolean variable. -- cgit v1.3.1