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-class-pwm | 88 +++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-pwm (limited to 'Documentation/ABI/testing/sysfs-class-pwm') diff --git a/Documentation/ABI/testing/sysfs-class-pwm b/Documentation/ABI/testing/sysfs-class-pwm new file mode 100644 index 000000000..0638c94d0 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-pwm @@ -0,0 +1,88 @@ +What: /sys/class/pwm/ +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + The pwm/ class sub-directory belongs to the Generic PWM + Framework and provides a sysfs interface for using PWM + channels. + +What: /sys/class/pwm/pwmchip/ +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + A /sys/class/pwm/pwmchipN directory is created for each + probed PWM controller/chip where N is the base of the + PWM chip. + +What: /sys/class/pwm/pwmchip/npwm +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + The number of PWM channels supported by the PWM chip. + +What: /sys/class/pwm/pwmchip/export +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Exports a PWM channel from the PWM chip for sysfs control. + Value is between 0 and /sys/class/pwm/pwmchipN/npwm - 1. + +What: /sys/class/pwm/pwmchip/unexport +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Unexports a PWM channel. + +What: /sys/class/pwm/pwmchip/pwmX +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + A /sys/class/pwm/pwmchipN/pwmX directory is created for + each exported PWM channel where X is the exported PWM + channel number. + +What: /sys/class/pwm/pwmchip/pwmX/period +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Sets the PWM signal period in nanoseconds. + +What: /sys/class/pwm/pwmchip/pwmX/duty_cycle +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Sets the PWM signal duty cycle in nanoseconds. + +What: /sys/class/pwm/pwmchip/pwmX/polarity +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Sets the output polarity of the PWM signal to "normal" or + "inversed". + +What: /sys/class/pwm/pwmchip/pwmX/enable +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Enable/disable the PWM signal. + 0 is disabled + 1 is enabled + +What: /sys/class/pwm/pwmchip/pwmX/capture +Date: June 2016 +KernelVersion: 4.8 +Contact: Lee Jones +Description: + Capture information about a PWM signal. The output format is a + pair unsigned integers (period and duty cycle), separated by a + single space. -- cgit v1.3.1