On 8/27/2025 5:01 PM, Sean Christopherson wrote:
> Use the kernel's common "entry virt" APIs to handle pending work prior to
> (re)entering guest mode, now that the virt APIs don't have a superfluous
> dependency on KVM.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> drivers/hv/Kconfig | 1 +
> drivers/hv/mshv_root_main.c | 32 ++++++--------------------------
> 2 files changed, 7 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
> index 2e8df09db599..894037afcbf9 100644
> --- a/drivers/hv/Kconfig
> +++ b/drivers/hv/Kconfig
> @@ -66,6 +66,7 @@ config MSHV_ROOT
> # no particular order, making it impossible to reassemble larger pages
> depends on PAGE_SIZE_4KB
> select EVENTFD
> + select VIRT_XFER_TO_GUEST_WORK
> default n
> help
> Select this option to enable support for booting and running as root
> diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
> index 0d849f09160a..7c83f656e071 100644
> --- a/drivers/hv/mshv_root_main.c
> +++ b/drivers/hv/mshv_root_main.c
> @@ -8,6 +8,7 @@
> * Authors: Microsoft Linux virtualization team
> */
>
> +#include <linux/entry-virt.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/fs.h>
> @@ -481,29 +482,6 @@ mshv_vp_wait_for_hv_kick(struct mshv_vp *vp)
> return 0;
> }
>
> -static int mshv_pre_guest_mode_work(struct mshv_vp *vp)
> -{
> - const ulong work_flags = _TIF_NOTIFY_SIGNAL | _TIF_SIGPENDING |
> - _TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY |
> - _TIF_NOTIFY_RESUME;
> - ulong th_flags;
> -
> - th_flags = read_thread_flags();
> - while (th_flags & work_flags) {
> - int ret;
> -
> - /* nb: following will call schedule */
> - ret = mshv_do_pre_guest_mode_work(th_flags);
> -
> - if (ret)
> - return ret;
> -
> - th_flags = read_thread_flags();
> - }
> -
> - return 0;
> -}
> -
> /* Must be called with interrupts enabled */
> static long mshv_run_vp_with_root_scheduler(struct mshv_vp *vp)
> {
> @@ -524,9 +502,11 @@ static long mshv_run_vp_with_root_scheduler(struct mshv_vp *vp)
> u32 flags = 0;
> struct hv_output_dispatch_vp output;
>
> - ret = mshv_pre_guest_mode_work(vp);
> - if (ret)
> - break;
> + if (__xfer_to_guest_mode_work_pending()) {
> + ret = xfer_to_guest_mode_handle_work();
> + if (ret)
> + break;
> + }
>
> if (vp->run.flags.intercept_suspend)
> flags |= HV_DISPATCH_VP_FLAG_CLEAR_INTERCEPT_SUSPEND;
Also tested mshv_root with 1-6 applied, looks good to me. Possibly Naman,
Saurabh, or Roman can test the mshv_vtl patches, I can't do it
unfortunately.
Tested-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>