Re: [PATCH v5 4/7] kvmppc: Handle memory plug/unplug to secure VM

[janani <janani@linux.ibm.com>]

On 2019-07-09 05:25, Bharata B Rao wrote:
> Register the new memslot with UV during plug and unregister
> the memslot during unplug.
> 
> Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
> Acked-by: Paul Mackerras <paulus@ozlabs.org>
  Reviewed-by: Janani Janakiraman <janani@linux.ibm.com>
> ---
>  arch/powerpc/include/asm/ultravisor-api.h |  1 +
>  arch/powerpc/include/asm/ultravisor.h     |  7 +++++++
>  arch/powerpc/kvm/book3s_hv.c              | 19 +++++++++++++++++++
>  3 files changed, 27 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/ultravisor-api.h
> b/arch/powerpc/include/asm/ultravisor-api.h
> index 07b7d638e7af..d6d6eb2e6e6b 100644
> --- a/arch/powerpc/include/asm/ultravisor-api.h
> +++ b/arch/powerpc/include/asm/ultravisor-api.h
> @@ -21,6 +21,7 @@
>  #define UV_WRITE_PATE			0xF104
>  #define UV_RETURN			0xF11C
>  #define UV_REGISTER_MEM_SLOT		0xF120
> +#define UV_UNREGISTER_MEM_SLOT		0xF124
>  #define UV_PAGE_IN			0xF128
>  #define UV_PAGE_OUT			0xF12C
> 
> diff --git a/arch/powerpc/include/asm/ultravisor.h
> b/arch/powerpc/include/asm/ultravisor.h
> index b46042f1aa8f..fe45be9ee63b 100644
> --- a/arch/powerpc/include/asm/ultravisor.h
> +++ b/arch/powerpc/include/asm/ultravisor.h
> @@ -70,6 +70,13 @@ static inline int uv_register_mem_slot(u64 lpid,
> u64 start_gpa, u64 size,
>  	return ucall(UV_REGISTER_MEM_SLOT, retbuf, lpid, start_gpa,
>  		     size, flags, slotid);
>  }
> +
> +static inline int uv_unregister_mem_slot(u64 lpid, u64 slotid)
> +{
> +	unsigned long retbuf[UCALL_BUFSIZE];
> +
> +	return ucall(UV_UNREGISTER_MEM_SLOT, retbuf, lpid, slotid);
> +}
>  #endif /* !__ASSEMBLY__ */
> 
>  #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
> diff --git a/arch/powerpc/kvm/book3s_hv.c 
> b/arch/powerpc/kvm/book3s_hv.c
> index b8f801d00ad4..7cbb5edaed01 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -77,6 +77,7 @@
>  #include <asm/hw_breakpoint.h>
>  #include <asm/kvm_host.h>
>  #include <asm/kvm_book3s_hmm.h>
> +#include <asm/ultravisor.h>
> 
>  #include "book3s.h"
> 
> @@ -4504,6 +4505,24 @@ static void
> kvmppc_core_commit_memory_region_hv(struct kvm *kvm,
>  	if (change == KVM_MR_FLAGS_ONLY && kvm_is_radix(kvm) &&
>  	    ((new->flags ^ old->flags) & KVM_MEM_LOG_DIRTY_PAGES))
>  		kvmppc_radix_flush_memslot(kvm, old);
> +	/*
> +	 * If UV hasn't yet called H_SVM_INIT_START, don't register memslots.
> +	 */
> +	if (!kvm->arch.secure_guest)
> +		return;
> +
> +	/*
> +	 * TODO: Handle KVM_MR_MOVE
> +	 */
> +	if (change == KVM_MR_CREATE) {
> +		uv_register_mem_slot(kvm->arch.lpid,
> +					   new->base_gfn << PAGE_SHIFT,
> +					   new->npages * PAGE_SIZE,
> +					   0,
> +					   new->id);
> +	} else if (change == KVM_MR_DELETE) {
> +		uv_unregister_mem_slot(kvm->arch.lpid, old->id);
> +	}
>  }
> 
>  /*